Warning fixes

Tests/ZeroLevel.UnitTests/Models/TestSerializableDTO.cs

@@ -37,5 +37,10 @@ namespace ZeroLevel.UnitTests.Models
             writer.WriteString(this.Title);
             writer.WriteLong(this.Timestamp);
         }
+
+        public override int GetHashCode()
+        {
+            return Id.GetHashCode() ^ (Title?.GetHashCode() ?? 0) ^ Timestamp.GetHashCode();
+        }
     }
 }

Tests/ZeroLevel.UnitTests/TokenEncryptorTest.cs

@@ -37,6 +37,11 @@ namespace ZeroLevel.UnitTests
                 writer.WriteString(this.Login);
                 writer.WriteString(this.Name);
             }
+
+            public override int GetHashCode()
+            {
+                return (Login?.GetHashCode() ?? 0) ^ (Name?.GetHashCode() ?? 0);
+            }
         }
 
         [Fact]

ZeroLevel.ML/ImageMetainfo.cs

@@ -104,7 +104,7 @@ p2 pixel units = -p2 focal units / focal length
 
     public sealed class ImageMetainfo
     {
-        private CameraMath _camera = null;
+        private CameraMath _camera = null!;
         public CameraMath CreateCamera()
         {
             if (_camera == null)

ZeroLevel.ML/ZeroLevel.ML.csproj

@@ -5,6 +5,9 @@
 		<TargetFramework>netstandard2.1</TargetFramework>
 		<Nullable>enable</Nullable>
 		<AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+		<FileVersion>$(AssemblyVersion)</FileVersion>
+		<AssemblyVersion>4.0.0.0</AssemblyVersion>
+		<Version>$(AssemblyVersion)</Version>
 	</PropertyGroup>
 
 	<ItemGroup>

ZeroLevel.MsSql/ZeroLevel.MsSql.csproj

@@ -1,16 +1,20 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
+	<PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+		<LangVersion>latest</LangVersion>
-    <Nullable>enable</Nullable>
+		<TargetFramework>netstandard2.1</TargetFramework>
-  </PropertyGroup>
+		<Nullable>enable</Nullable>
+		<FileVersion>$(AssemblyVersion)</FileVersion>
+		<AssemblyVersion>4.0.0.0</AssemblyVersion>
+		<Version>$(AssemblyVersion)</Version>
+	</PropertyGroup>
 
-  <ItemGroup>
+	<ItemGroup>
-    <PackageReference Include="System.Data.SqlClient" Version="4.8.6" />
+		<PackageReference Include="System.Data.SqlClient" Version="4.8.6" />
-  </ItemGroup>
+	</ItemGroup>
 
-  <ItemGroup>
+	<ItemGroup>
-    <ProjectReference Include="..\ZeroLevel\ZeroLevel.csproj" />
+		<ProjectReference Include="..\ZeroLevel\ZeroLevel.csproj" />
-  </ItemGroup>
+	</ItemGroup>
 
 </Project>

ZeroLevel.Sleopok.Engine/ZeroLevel.Sleopok.Engine.csproj

@@ -1,12 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <PropertyGroup>
+	<PropertyGroup>
-    <TargetFramework>netstandard2.1</TargetFramework>
+		<LangVersion>latest</LangVersion>
-    <Nullable>enable</Nullable>
+		<TargetFramework>netstandard2.1</TargetFramework>
-  </PropertyGroup>
+		<Nullable>enable</Nullable>
+		<FileVersion>$(AssemblyVersion)</FileVersion>
+		<AssemblyVersion>4.0.0.0</AssemblyVersion>
+		<Version>$(AssemblyVersion)</Version>
+	</PropertyGroup>
 
-  <ItemGroup>
+	<ItemGroup>
-    <ProjectReference Include="..\ZeroLevel\ZeroLevel.csproj" />
+		<ProjectReference Include="..\ZeroLevel\ZeroLevel.csproj" />
-  </ItemGroup>
+	</ItemGroup>
 
 </Project>

ZeroLevel/DataStructures/SparseMatrix.cs

@@ -56,7 +56,7 @@ namespace ZeroLevel.DataStructures
                 }
 
                 //If there is no item on the given position return defaault value
-                return default(T);
+                return default(T)!;
             }
             set
             {

ZeroLevel/Models/ZeroServiceInfo.cs

@@ -42,7 +42,7 @@ namespace ZeroLevel
 
         public bool Equals(ZeroServiceInfo other)
         {
-            if (other == null) return false;
+            if (other == null!) return false;
             if (object.ReferenceEquals(this, other)) return true;
             if (string.Compare(this.Name, other.Name, true) != 0) return false;
             if (string.Compare(this.ServiceKey, other.ServiceKey, true) != 0) return false;
@@ -54,7 +54,7 @@ namespace ZeroLevel
 
         public override bool Equals(object obj)
         {
-            return this.Equals(obj as ZeroServiceInfo);
+            return this.Equals((obj as ZeroServiceInfo)!);
         }
 
         public override int GetHashCode()

ZeroLevel/Services/BaseZeroService.cs

@@ -127,7 +127,7 @@ namespace ZeroLevel.Services.Applications
                     }
                 }
             }
-            return default(T);
+            return default(T)!;
         }
         #endregion Config
 

ZeroLevel/Services/Bootstrap.cs

@@ -29,7 +29,7 @@ namespace ZeroLevel
 
             public BootstrapFluent(IZeroService service)
             {
-                if (service == null)
+                if (service == null!)
                 {
                     throw new ArgumentNullException(nameof(service));
                 }
@@ -56,7 +56,7 @@ namespace ZeroLevel
                 catch (Exception ex)
                 {
                     Log.Error(ex, $"[Bootstrap] Service {_service?.Name} run error");
-                    return null;
+                    return null!;
                 }
                 return this;
             }
@@ -108,7 +108,7 @@ namespace ZeroLevel
             {
                 Log.Info($"[Bootstrap] Resolve assembly '{args.Name}' {args.Name}");
                 string name = args.Name.Split(',')[0];
-                if (name.EndsWith(".resources")) return null;
+                if (name.EndsWith(".resources")) return null!;
                 foreach (string file in Directory.
                     GetFiles(Path.Combine(Configuration.BaseDirectory), "*.dll", SearchOption.TopDirectoryOnly))
                 {
@@ -123,7 +123,7 @@ namespace ZeroLevel
             {
                 Log.Error(ex, $"[Bootstrap] Fault load assembly '{args.Name}'");
             }
-            return null;
+            return null!;
         }
 
         public static BootstrapFluent Startup<T>(string[] args,
@@ -155,13 +155,13 @@ namespace ZeroLevel
             IZeroService service = null!;
             IConfigurationSet config = Configuration.DefaultSet;
             config.CreateSection("commandline", Configuration.ReadFromCommandLine(args));
-            if (configurationSet != null)
+            if (configurationSet != null!)
             {
                 config.Merge(configurationSet);
             }
             Log.CreateLoggingFromConfiguration(Configuration.DefaultSet);
 
-            if (preStartConfiguration != null)
+            if (preStartConfiguration != null!)
             {
                 try
                 {
@@ -185,20 +185,20 @@ namespace ZeroLevel
             {
                 Log.SystemError(ex, "[Bootstrap] Service start canceled, service constructor call fault");
             }
-            if (postStartConfiguration != null)
+            if (postStartConfiguration != null!)
             {
                 try
                 {
                     if (postStartConfiguration() == false)
                     {
                         Log.SystemInfo("[Bootstrap] Service start canceled, because custom postconfig return false");
-                        return null;
+                        return null!;
                     }
                 }
                 catch (Exception ex)
                 {
                     Log.SystemError(ex, "[Bootstrap] Service start canceled, postconfig faulted");
-                    return null;
+                    return null!;
                 }
             }
             return service;

ZeroLevel/Services/Cache/LRUCache.cs

@@ -58,7 +58,7 @@ namespace ZeroLevel.Services.Cache
                 }
             }
 
-            value = default(TValue);
+            value = default(TValue)!;
             return false;
         }
 

ZeroLevel/Services/Cache/TimerCachee.cs

@@ -62,7 +62,7 @@ namespace ZeroLevel.Services.Cache
                 {
                     try
                     {
-                        if (_onDisposeAction != null)
+                        if (_onDisposeAction != null!)
                         {
                             _onDisposeAction.Invoke(v.Value);
                         }
@@ -92,7 +92,7 @@ namespace ZeroLevel.Services.Cache
                 {
                     try
                     {
-                        if (_onDisposeAction != null)
+                        if (_onDisposeAction != null!)
                         {
                             _onDisposeAction.Invoke(_cachee[key].Value);
                         }
@@ -114,7 +114,7 @@ namespace ZeroLevel.Services.Cache
                 {
                     try
                     {
-                        if (_onDisposeAction != null)
+                        if (_onDisposeAction != null!)
                         {
                             _onDisposeAction.Invoke(pair.Value.Value);
                         }

ZeroLevel/Services/Collections/Capacitor.cs

@@ -18,7 +18,7 @@ namespace ZeroLevel.Services.Collections
         public Capacitor(int dischargeValue, Action<T[], int> dischargeAction)
         {
             if (dischargeValue < 1) dischargeValue = 16;
-            if (dischargeAction == null) throw new ArgumentNullException(nameof(dischargeAction));
+            if (dischargeAction == null!) throw new ArgumentNullException(nameof(dischargeAction));
             _buffer = new T[dischargeValue];
             _dischargeAction = dischargeAction;
         }

ZeroLevel/Services/Collections/ConcurrentHashSet.cs

@@ -187,7 +187,7 @@ namespace ZeroLevel.Collections
         public ConcurrentHashSet(IEnumerable<T> collection, IEqualityComparer<T> comparer)
             : this(comparer)
         {
-            if (collection == null) throw new ArgumentNullException(nameof(collection));
+            if (collection == null!) throw new ArgumentNullException(nameof(collection));
 
             InitializeFromCollection(collection);
         }
@@ -214,7 +214,7 @@ namespace ZeroLevel.Collections
         public ConcurrentHashSet(int concurrencyLevel, IEnumerable<T> collection, IEqualityComparer<T> comparer)
             : this(concurrencyLevel, DefaultCapacity, false, comparer)
         {
-            if (collection == null) throw new ArgumentNullException(nameof(collection));
+            if (collection == null!) throw new ArgumentNullException(nameof(collection));
 
             InitializeFromCollection(collection);
         }
@@ -337,7 +337,7 @@ namespace ZeroLevel.Collections
             // The Volatile.Read ensures that the load of the fields of 'n' doesn't move before the load from buckets[i].
             var current = Volatile.Read(ref tables.Buckets[bucketNo]);
 
-            while (current != null)
+            while (current != null!)
             {
                 if (hashcode == current.Hashcode && _comparer.Equals(current.Item, equalValue))
                 {
@@ -348,7 +348,7 @@ namespace ZeroLevel.Collections
                 current = current.Next;
             }
 
-            actualValue = default;
+            actualValue = default!;
             return false;
         }
 
@@ -376,13 +376,13 @@ namespace ZeroLevel.Collections
                     }
 
                     Node previous = null!;
-                    for (var current = tables.Buckets[bucketNo]; current != null; current = current.Next)
+                    for (var current = tables.Buckets[bucketNo]; current != null!; current = current.Next)
                     {
                         Debug.Assert((previous == null && current == tables.Buckets[bucketNo]) || previous!.Next == current);
 
                         if (hashcode == current.Hashcode && _comparer.Equals(current.Item, item))
                         {
-                            if (previous == null)
+                            if (previous == null!)
                             {
                                 Volatile.Write(ref tables.Buckets[bucketNo], current.Next);
                             }
@@ -434,7 +434,7 @@ namespace ZeroLevel.Collections
             // Provides a manually-implemented version of (approximately) this iterator:
             //     Node?[] buckets = _tables.Buckets;
             //     for (int i = 0; i < buckets.Length; i++)
-            //         for (Node? current = Volatile.Read(ref buckets[i]); current != null; current = current.Next)
+            //         for (Node? current = Volatile.Read(ref buckets[i]); current != null!; current = current.Next)
             //             yield return new current.Item;
 
             private readonly ConcurrentHashSet<T> _set;
@@ -502,7 +502,7 @@ namespace ZeroLevel.Collections
 
                     case StateOuterloop:
                         Node[] buckets = _buckets;
-                        Debug.Assert(buckets != null);
+                        Debug.Assert(buckets != null!);
 
                         int i = ++_i;
                         if ((uint)i < (uint)buckets!.Length)
@@ -517,7 +517,7 @@ namespace ZeroLevel.Collections
 
                     case StateInnerLoop:
                         Node node = _node;
-                        if (node != null)
+                        if (node != null!)
                         {
                             Current = node.Item;
                             _node = node.Next;
@@ -538,7 +538,7 @@ namespace ZeroLevel.Collections
 
         void ICollection<T>.CopyTo(T[] array, int arrayIndex)
         {
-            if (array == null) throw new ArgumentNullException(nameof(array));
+            if (array == null!) throw new ArgumentNullException(nameof(array));
             if (arrayIndex < 0) throw new ArgumentOutOfRangeException(nameof(arrayIndex));
 
             var locksAcquired = 0;
@@ -606,8 +606,8 @@ namespace ZeroLevel.Collections
                     }
 
                     // Try to find this item in the bucket
-                    Node previous = null;
+                    Node previous = null!;
-                    for (var current = tables.Buckets[bucketNo]; current != null; current = current.Next)
+                    for (var current = tables.Buckets[bucketNo]; current != null!; current = current.Next)
                     {
                         Debug.Assert(previous == null && current == tables.Buckets[bucketNo] || previous!.Next == current);
                         if (hashcode == current.Hashcode && _comparer.Equals(current.Item, item))
@@ -791,7 +791,7 @@ namespace ZeroLevel.Collections
                 for (var i = 0; i < tables.Buckets.Length; i++)
                 {
                     var current = tables.Buckets[i];
-                    while (current != null)
+                    while (current != null!)
                     {
                         var next = current.Next;
                         GetBucketAndLockNo(current.Hashcode, out int newBucketNo, out int newLockNo, newBuckets.Length, newLocks.Length);
@@ -868,7 +868,7 @@ namespace ZeroLevel.Collections
             var buckets = _tables.Buckets;
             for (var i = 0; i < buckets.Length; i++)
             {
-                for (var current = buckets[i]; current != null; current = current.Next)
+                for (var current = buckets[i]; current != null!; current = current.Next)
                 {
                     array[index] = current.Item;
                     index++; //this should never flow, CopyToItems is only called when there's no overflow risk

ZeroLevel/Services/Collections/EverythingStorage.cs

@@ -59,14 +59,14 @@ namespace ZeroLevel.Services.Collections
 
             public void Insert<T>(string key, T entity)
             {
-                _insert.Invoke(_instance, new object[] { key, entity });
+                _insert.Invoke(_instance, new object[] { key, entity! });
             }
 
             public void InsertOrUpdate<T>(string key, T entity)
             {
                 if ((bool)_containsKey.Invoke(_instance, key))
                     _remove.Invoke(_instance, key);
-                _insert.Invoke(_instance, new object[] { key, entity });
+                _insert.Invoke(_instance, new object[] { key, entity! });
             }
 
             public bool ContainsKey(string key)

ZeroLevel/Services/Collections/FastBitArray.cs

@@ -62,7 +62,7 @@ namespace ZeroLevel.Collections
         =========================================================================*/
         public FastBitArray(byte[] bytes)
         {
-            if (bytes == null)
+            if (bytes == null!)
             {
                 throw new ArgumentNullException(nameof(bytes));
             }
@@ -135,7 +135,7 @@ namespace ZeroLevel.Collections
 
         private void SetValues(int[] values)
         {
-            if (values == null)
+            if (values == null!)
             {
                 throw new ArgumentNullException(nameof(values));
             }
@@ -157,7 +157,7 @@ namespace ZeroLevel.Collections
             =========================================================================*/
         public FastBitArray(FastBitArray bits)
         {
-            if (bits == null)
+            if (bits == null!)
             {
                 throw new ArgumentNullException(nameof(bits));
             }
@@ -183,7 +183,7 @@ namespace ZeroLevel.Collections
 
         private void SetValues(bool[] values)
         {
-            if (values == null)
+            if (values == null!)
             {
                 throw new ArgumentNullException(nameof(values));
             }
@@ -276,7 +276,7 @@ namespace ZeroLevel.Collections
         =========================================================================*/
         public FastBitArray And(FastBitArray value)
         {
-            if (value == null)
+            if (value == null!)
                 throw new ArgumentNullException(nameof(value));
             if (Length != value.Length)
                 throw new ArgumentException("The array lengths differ.");
@@ -303,7 +303,7 @@ namespace ZeroLevel.Collections
         =========================================================================*/
         public FastBitArray Or(FastBitArray value)
         {
-            if (value == null)
+            if (value == null!)
                 throw new ArgumentNullException(nameof(value));
             if (Length != value.Length)
                 throw new ArgumentException("The array lengths differ");
@@ -385,7 +385,7 @@ namespace ZeroLevel.Collections
         =========================================================================*/
         public FastBitArray Xor(FastBitArray value)
         {
-            if (value == null)
+            if (value == null!)
                 throw new ArgumentNullException(nameof(value));
             if (Length != value.Length)
                 throw new ArgumentException("The array lengths differ");
@@ -465,7 +465,7 @@ namespace ZeroLevel.Collections
         // ICollection implementation
         public void CopyTo(Array array, int index)
         {
-            if (array == null)
+            if (array == null!)
                 throw new ArgumentNullException(nameof(array));
             if (index < 0)
                 throw new ArgumentOutOfRangeException(nameof(index), "The index cannot be less than 0.");
@@ -508,7 +508,7 @@ namespace ZeroLevel.Collections
 
         public Object Clone()
         {
-            Contract.Ensures(Contract.Result<Object>() != null);
+            Contract.Ensures(Contract.Result<Object>() != null!);
             Contract.Ensures(((FastBitArray)Contract.Result<Object>()).Length == this.Length);
             return new FastBitArray(this);
         }
@@ -517,9 +517,9 @@ namespace ZeroLevel.Collections
         {
             get
             {
-                if (_syncRoot == null)
+                if (_syncRoot == null!)
                 {
-                    System.Threading.Interlocked.CompareExchange<Object>(ref _syncRoot, new Object(), null);
+                    System.Threading.Interlocked.CompareExchange<Object>(ref _syncRoot!, new Object(), null!);
                 }
                 return _syncRoot;
             }

ZeroLevel/Services/Collections/FixSizeQueue.cs

@@ -45,8 +45,8 @@ namespace ZeroLevel.Services.Collections
 
         public bool Equals(T x, T y)
         {
-            if (x == null && y == null) return true;
+            if (x == null && y == null!) return true;
-            if (x == null || y == null) return false;
+            if (x == null || y == null!) return false;
             if ((object)x == (object)y) return true;
             if (ReferenceEquals(x, y)) return true;
             return x.Equals(y);
@@ -57,7 +57,7 @@ namespace ZeroLevel.Services.Collections
             lock (_accessLocker)
             {
                 Func<T, T, bool> eq_func;
-                if (comparer == null)
+                if (comparer == null!)
                 {
                     eq_func = Equals;
                 }
@@ -94,13 +94,13 @@ namespace ZeroLevel.Services.Collections
                 if (_count > 0)
                 {
                     t = _array[_startIndex];
-                    _array[_startIndex] = default(T);
+                    _array[_startIndex] = default(T)!;
                     _startIndex = (_startIndex + 1) % _array.Length;
                     _count--;
                     return true;
                 }
             }
-            t = default(T);
+            t = default(T)!;
             return false;
         }
 
@@ -112,7 +112,7 @@ namespace ZeroLevel.Services.Collections
                 if (_count > 0)
                 {
                     ret = _array[_startIndex];
-                    _array[_startIndex] = default(T);
+                    _array[_startIndex] = default(T)!;
                     _startIndex = (_startIndex + 1) % _array.Length;
                     _count--;
                     return ret;

ZeroLevel/Services/Collections/IFixSizeQueue.cs

@@ -14,6 +14,6 @@ namespace ZeroLevel.Services.Collections
 
         IEnumerable<T> Dump();
 
-        bool Contains(T item, IComparer<T> comparer = null);
+        bool Contains(T item, IComparer<T> comparer = null!);
     }
 }

ZeroLevel/Services/Collections/KeyListValueTransactCollection.cs

@@ -208,7 +208,7 @@ namespace ZeroLevel.Services.Collections
         {
             if (disposing)
             {
-                if (_collection != null)
+                if (_collection != null!)
                 {
                     _collection.Clear();
                 }

ZeroLevel/Services/Collections/KeyValueTransactCollection.cs

@@ -179,7 +179,7 @@ namespace ZeroLevel.Services.Collections
             }
             else
             {
-                if (!_collection[id].Equals(value))
+                if (!_collection[id]!.Equals(value))
                 {
                     if (false == _updatedRecords.ContainsKey(id))
                     {
@@ -254,12 +254,12 @@ namespace ZeroLevel.Services.Collections
         {
             if (disposing)
             {
-                if (_collection != null)
+                if (_collection != null!)
                 {
                     foreach (TKey key in _collection.Keys)
                     {
                         var disposable = _collection[key] as IDisposable;
-                        if (disposable != null)
+                        if (disposable != null!)
                             disposable.Dispose();
                     }
                     _collection.Clear();

ZeroLevel/Services/Collections/RoundRobinCollection.cs

@@ -147,7 +147,7 @@ namespace ZeroLevel.Services.Collections
         {
             get
             {
-                return _index == -1 ? default(T) : _collection[_index];
+                return (_index == -1 ? default(T) : _collection[_index])!;
             }
         }
 

ZeroLevel/Services/Collections/ZPriorityQueue.cs

@@ -18,15 +18,15 @@ namespace ZeroLevel.Services.Collections
     public class ZPriorityQueue<T>
         : IPriorityQueue<T>
     {
-        private sealed class PriorityQueueObject<T>
+        private sealed class PriorityQueueObject<T1>
         {
             public readonly int Priority;
 
-            public readonly T Value;
+            public readonly T1 Value;
 
-            public PriorityQueueObject<T> Next;
+            public PriorityQueueObject<T1> Next;
 
-            public PriorityQueueObject(T val, int priority)
+            public PriorityQueueObject(T1 val, int priority)
             {
                 Value = val;
                 Priority = priority;
@@ -34,7 +34,7 @@ namespace ZeroLevel.Services.Collections
         }
 
         private readonly Func<T, PriorityQueueObjectHandleResult> _handler;
-        private PriorityQueueObject<T> _head = null;
+        private PriorityQueueObject<T> _head = null!;
         private readonly object _rw_lock = new object();
         private int _counter = 0;
 
@@ -42,7 +42,7 @@ namespace ZeroLevel.Services.Collections
 
         public ZPriorityQueue(Func<T, PriorityQueueObjectHandleResult> handler)
         {
-            if (handler == null)
+            if (handler == null!)
                 throw new ArgumentNullException(nameof(handler));
             _handler = handler;
         }
@@ -59,7 +59,7 @@ namespace ZeroLevel.Services.Collections
                 else
                 {
                     var cursor = _head;
-                    PriorityQueueObject<T> prev = null;
+                    PriorityQueueObject<T> prev = null!;
                     do
                     {
                         if (cursor.Priority > insert.Priority)
@@ -77,11 +77,11 @@ namespace ZeroLevel.Services.Collections
                         }
                         prev = cursor;
                         cursor = cursor.Next;
-                        if (cursor == null)
+                        if (cursor == null!)
                         {
                             prev.Next = insert;
                         }
-                    } while (cursor != null);
+                    } while (cursor != null!);
                 }
                 _counter++;
             }
@@ -90,17 +90,17 @@ namespace ZeroLevel.Services.Collections
 
         public T HandleCurrentItem()
         {
-            T v = default(T);
+            T v = default(T)!;
             lock (_rw_lock)
             {
                 var item = _head;
-                PriorityQueueObject<T> prev = null;
+                PriorityQueueObject<T> prev = null!;
-                while (item != null)
+                while (item != null!)
                 {
                     var result = this._handler.Invoke(item.Value);
                     if (result.IsCompleted)
                     {
-                        if (prev != null)
+                        if (prev != null!)
                         {
                             prev.Next = item.Next;
                         }

ZeroLevel/Services/Config/BaseConfiguration.cs

@@ -118,7 +118,7 @@ namespace ZeroLevel.Services.Config
             {
                 if (result.Count > 0)
                     return result[0];
-                return null;
+                return null!;
             }
             throw new KeyNotFoundException("Key not found: " + key);
         }
@@ -154,7 +154,7 @@ namespace ZeroLevel.Services.Config
                 {
                     return (T)StringToTypeConverter.TryConvert(result[0], typeof(T));
                 }
-                return default(T);
+                return default(T)!;
             }
             throw new KeyNotFoundException("Parameter not found: " + key);
         }
@@ -192,7 +192,7 @@ namespace ZeroLevel.Services.Config
                     return (T)StringToTypeConverter.TryConvert(result[0], typeof(T));
                 }
             }
-            return default(T);
+            return default(T)!;
         }
 
         /// <summary>
@@ -280,7 +280,7 @@ namespace ZeroLevel.Services.Config
                 {
                     _keyValues.TryAdd(key, new List<string>());
                 }
-                _keyValues[key].Add(value?.Trim() ?? null);
+                _keyValues[key].Add((value?.Trim() ?? null)!);
             }
             return this;
         }
@@ -296,7 +296,7 @@ namespace ZeroLevel.Services.Config
                 }
                 foreach (var value in values)
                 {
-                    _keyValues[key].Add(value?.Trim() ?? null);
+                    _keyValues[key].Add((value?.Trim() ?? null)!);
                 }
             }
             return this;
@@ -318,7 +318,7 @@ namespace ZeroLevel.Services.Config
                 {
                     _keyValues[key].Clear();
                 }
-                _keyValues[key].Add(value?.Trim() ?? null);
+                _keyValues[key].Add((value?.Trim() ?? null)!);
             }
             return this;
         }
@@ -360,8 +360,7 @@ namespace ZeroLevel.Services.Config
         {
             if (false == _freezed)
             {
-                IList<string> removed;
+                _keyValues.TryRemove(GetKey(key), out _);
-                _keyValues.TryRemove(GetKey(key), out removed);
             }
             return this;
         }
@@ -404,7 +403,7 @@ namespace ZeroLevel.Services.Config
 
         public bool Equals(IConfiguration other)
         {
-            if (other == null)
+            if (other == null!)
             {
                 return false;
             }
@@ -508,12 +507,12 @@ namespace ZeroLevel.Services.Config
                 if (count > 0)
                 {
                     var values = this.Items(member.Name);
-                    IConfigRecordParser parser = member.Original.GetCustomAttribute<ConfigRecordParseAttribute>()?.Parser;
+                    IConfigRecordParser parser = member.Original.GetCustomAttribute<ConfigRecordParseAttribute>()?.Parser!;
                     if (TypeHelpers.IsArray(member.ClrType) && member.ClrType.GetArrayRank() == 1)
                     {
                         int index = 0;
                         var itemType = member.ClrType.GetElementType();
-                        if (parser == null)
+                        if (parser == null!)
                         {
                             var elements = values.SelectMany(v => SplitRange(v, itemType)).ToArray();
                             var arrayBuilder = CollectionFactory.CreateArray(itemType, elements.Length);
@@ -540,7 +539,7 @@ namespace ZeroLevel.Services.Config
                     {
                         var itemType = member.ClrType.GenericTypeArguments.First();
                         var collectionBuilder = CollectionFactory.Create(itemType);
-                        if (parser == null)
+                        if (parser == null!)
                         {
                             var elements = values.SelectMany(v => SplitRange(v, itemType)).ToArray();
                             foreach (var item in elements)
@@ -561,7 +560,7 @@ namespace ZeroLevel.Services.Config
                     else
                     {
                         var single = values.First();
-                        if (parser != null)
+                        if (parser != null!)
                         {
                             member.Setter(instance, parser.Parse(single));
                         }

ZeroLevel/Services/Config/BaseConfigurationSet.cs

@@ -158,7 +158,7 @@ namespace ZeroLevel.Services.Config
 
         public bool Equals(IConfigurationSet other)
         {
-            if (other == null) return false;
+            if (other == null!) return false;
             return this.SectionNames.NoOrderingEquals(other.SectionNames) &&
                 this.Sections.NoOrderingEquals(other.Sections);
         }
@@ -274,14 +274,17 @@ namespace ZeroLevel.Services.Config
         {
             var mapper = TypeMapper.Create<T>(true);
             var instance = Default.Bind<T>();
-            mapper.TraversalMembers(member =>
+            if (instance != null)
             {
-                if (ContainsSection(member.Name))
+                mapper.TraversalMembers(member =>
                 {
-                    member.Setter(instance, GetSection(member.Name).Bind(member.ClrType));
+                    if (ContainsSection(member.Name))
-                }
+                    {
-            });
+                        member.Setter(instance, GetSection(member.Name).Bind(member.ClrType));
-            return instance;
+                    }
+                });
+            }
+            return instance!;
         }
     }
 }

ZeroLevel/Services/Config/ConfigRecordParseAttribute.cs

@@ -9,7 +9,7 @@ namespace ZeroLevel.Services.Config
 
         public ConfigRecordParseAttribute(Type parserType)
         {
-            if (parserType == null) throw new ArgumentNullException(nameof(parserType));
+            if (parserType == null!) throw new ArgumentNullException(nameof(parserType));
             Parser = (IConfigRecordParser)Activator.CreateInstance(parserType);
         }
     }

ZeroLevel/Services/Config/Configuration.cs

@@ -29,7 +29,7 @@ namespace ZeroLevel
             _emptySet.FreezeConfiguration(true);
             DefaultSet = Configuration.CreateSet();
             var assembly = EntryAssemblyAttribute.GetEntryAssembly();
-            if (assembly != null)
+            if (assembly != null!)
             {
                 BaseDirectory = Path.GetDirectoryName(assembly.Location);
                 AppLocation = assembly.Location;
@@ -52,7 +52,7 @@ namespace ZeroLevel
         public static IConfiguration Empty { get { return _empty; } }
         public static IConfigurationSet EmptySet { get { return _emptySet; } }
 
-        public static IConfiguration Default => DefaultSet?.Default;
+        public static IConfiguration Default => DefaultSet?.Default!;
         public static IConfigurationSet DefaultSet { get; private set; }
 
         public static void Save(string name, IConfiguration configuration)
@@ -62,7 +62,7 @@ namespace ZeroLevel
 
         public static void Save(IConfiguration configuration)
         {
-            if (DefaultSet == null)
+            if (DefaultSet == null!)
             {
                 DefaultSet = Configuration.CreateSet(configuration);
             }
@@ -79,7 +79,7 @@ namespace ZeroLevel
 
         public static void Save(IConfigurationSet configuration)
         {
-            if (DefaultSet == null)
+            if (DefaultSet == null!)
             {
                 DefaultSet = configuration;
             }

ZeroLevel/Services/Config/Implementation/AppWebConfigReader.cs

@@ -14,7 +14,7 @@ namespace ZeroLevel.Services.Config.Implementation
 
         internal AppWebConfigReader(string configFilePath = null!)
         {
-            if (configFilePath == null)
+            if (configFilePath == null!)
             {
                 var appConfig = Path.Combine(Configuration.BaseDirectory, $"{System.AppDomain.CurrentDomain.FriendlyName}.config");
                 if (File.Exists(appConfig))
@@ -49,7 +49,7 @@ namespace ZeroLevel.Services.Config.Implementation
 
         internal IEnumerable<string> GetSections()
         {
-            if (_configFilePath != null)
+            if (_configFilePath != null!)
             {
                 var xdoc = XDocument.Load(_configFilePath);
                 var cs = xdoc.Descendants("connectionStrings").
@@ -62,7 +62,7 @@ namespace ZeroLevel.Services.Config.Implementation
 
         internal IEnumerable<Tuple<string, string>> ReadSection(string sectionName)
         {
-            if (_configFilePath != null)
+            if (_configFilePath != null!)
             {
                 var xdoc = XDocument.Load(_configFilePath);
                 return xdoc.Descendants(sectionName).
@@ -78,7 +78,7 @@ namespace ZeroLevel.Services.Config.Implementation
 
         private static string FindName(XElement n)
         {
-            if (n == null) return string.Empty;
+            if (n == null!) return string.Empty;
             var attributes = n.Attributes().
                 ToDictionary(i => i.Name.LocalName.ToLowerInvariant(), j => j.Value);
             foreach (var v in new[] { "key", "name", "code", "id" })
@@ -91,7 +91,7 @@ namespace ZeroLevel.Services.Config.Implementation
 
         private static string FindValue(XElement n)
         {
-            if (n == null) return string.Empty;
+            if (n == null!) return string.Empty;
             var attributes = n.Attributes().
                 ToDictionary(i => i.Name.LocalName.ToLowerInvariant(), j => j.Value);
             foreach (var v in new[] { "value", "val", "file", "db", "connectionstring" })

ZeroLevel/Services/Config/Implementation/CommandLineReader.cs

@@ -16,7 +16,7 @@ namespace ZeroLevel.Services.Config.Implementation
         public IConfiguration ReadConfiguration()
         {
             var result = Configuration.Create();
-            if (_args != null)
+            if (_args != null!)
             {
                 try
                 {

ZeroLevel/Services/Config/Implementation/IniFileReader.cs

@@ -30,7 +30,7 @@ namespace ZeroLevel.Services.Config.Implementation
         public IConfiguration ReadConfiguration()
         {
             var result = Configuration.Create();
-            string sectionName = null;
+            string sectionName = null!;
             foreach (var line in File.ReadAllLines(_iniPath))
             {
                 if (string.IsNullOrWhiteSpace(line))
@@ -82,7 +82,7 @@ namespace ZeroLevel.Services.Config.Implementation
         public IConfigurationSet ReadConfigurationSet()
         {
             var result = Configuration.CreateSet();
-            string sectionName = null;
+            string sectionName = null!;
             foreach (var line in File.ReadAllLines(_iniPath))
             {
                 if (string.IsNullOrWhiteSpace(line))

ZeroLevel/Services/DOM/DSL/Contexts/TElementContext.cs

@@ -40,7 +40,7 @@ namespace DOM.DSL.Contexts
                             }
                             else
                             {
-                                _next = new TSystemToken { Command = name, Arg = null };
+                                _next = new TSystemToken { Command = name, Arg = null! };
                             }
                         }
                         else
@@ -72,7 +72,7 @@ namespace DOM.DSL.Contexts
 
         public TToken Complete()
         {
-            return new TElementToken { ElementName = _name, NextToken = _next?.Clone() };
+            return new TElementToken { ElementName = _name, NextToken = _next?.Clone()! };
         }
     }
 }

ZeroLevel/Services/DOM/DSL/Contexts/TFunctionContext.cs

@@ -38,7 +38,7 @@ namespace DOM.DSL.Contexts
             {
                 if (argTokens.Count > 0)
                 {
-                    _argTokens.Add(new TBlockToken("", null, argTokens.Select(t => t.Clone()).ToArray()));
+                    _argTokens.Add(new TBlockToken("", null!, argTokens.Select(t => t.Clone()).ToArray()));
                     argTokens.Clear();
                 }
             });
@@ -187,8 +187,8 @@ namespace DOM.DSL.Contexts
             return new TFunctionToken
             {
                 FunctionName = _name,
-                NextToken = _nextToken?.Clone(),
+                NextToken = _nextToken?.Clone()!,
-                FunctionArgs = _argTokens?.Select(t => t.Clone())
+                FunctionArgs = _argTokens?.Select(t => t.Clone())!
             };
         }
     }

ZeroLevel/Services/DOM/DSL/Contexts/TPropertyContext.cs

@@ -185,8 +185,8 @@ namespace DOM.DSL.Contexts
             return new TPropertyToken
             {
                 PropertyName = _name,
-                PropertyIndex = new TBlockToken(_name, null, _indexTokens.Select(t => t.Clone()).ToArray()),
+                PropertyIndex = new TBlockToken(_name, null!, _indexTokens.Select(t => t.Clone()).ToArray()),
-                NextToken = _nextToken?.Clone()
+                NextToken = _nextToken?.Clone()!
             };
         }
     }

ZeroLevel/Services/DOM/DSL/Contexts/TRootContext.cs

@@ -14,7 +14,7 @@ namespace DOM.DSL.Contexts
 
         public TRootContext()
         {
-            ParentContext = null;
+            ParentContext = null!;
             _tokens = new List<TToken>();
         }
 
@@ -109,7 +109,7 @@ namespace DOM.DSL.Contexts
                                     _tokens.Add(blockContext.Complete());
                                 }
                                 else if (ParentContext != null && ParentContext is TBlockContext &&
-                                    name.Equals("end" + (ParentContext as TBlockContext).Name, StringComparison.OrdinalIgnoreCase))
+                                    name.Equals("end" + (ParentContext as TBlockContext)!.Name, StringComparison.OrdinalIgnoreCase))
                                 {
                                     reader.Move(name.Length);
                                     flushTextToken();

ZeroLevel/Services/DOM/DSL/Model/TContentElement.cs

@@ -26,7 +26,7 @@ namespace DOM.DSL.Model
                 // Containers
                 case ContentElementType.Section:
                     var section = (element as Section);
-                    foreach (var item in section.Parts)
+                    foreach (var item in section!.Parts)
                     {
                         TraversElement(item, type, handler);
                     }
@@ -34,7 +34,7 @@ namespace DOM.DSL.Model
 
                 case ContentElementType.Paragraph:
                     var paragraph = (element as Paragraph);
-                    foreach (var item in paragraph.Parts)
+                    foreach (var item in paragraph!.Parts)
                     {
                         TraversElement(item, type, handler);
                     }
@@ -42,7 +42,7 @@ namespace DOM.DSL.Model
 
                 case ContentElementType.List:
                     var list = (element as List);
-                    foreach (var item in list.Items)
+                    foreach (var item in list!.Items)
                     {
                         TraversElement(item, type, handler);
                     }
@@ -50,7 +50,7 @@ namespace DOM.DSL.Model
 
                 case ContentElementType.Gallery:
                     var gallery = (element as Gallery);
-                    foreach (var item in gallery.Images)
+                    foreach (var item in gallery!.Images)
                     {
                         TraversElement(item, type, handler);
                     }
@@ -58,7 +58,7 @@ namespace DOM.DSL.Model
 
                 case ContentElementType.Audioplayer:
                     var audioplayer = (element as Audioplayer);
-                    foreach (var item in audioplayer.Tracks)
+                    foreach (var item in audioplayer!.Tracks)
                     {
                         TraversElement(item, type, handler);
                     }
@@ -66,7 +66,7 @@ namespace DOM.DSL.Model
 
                 case ContentElementType.Videoplayer:
                     var videoplayer = (element as Videoplayer);
-                    foreach (var item in videoplayer.Playlist)
+                    foreach (var item in videoplayer!.Playlist)
                     {
                         TraversElement(item, type, handler);
                     }
@@ -74,7 +74,7 @@ namespace DOM.DSL.Model
 
                 case ContentElementType.Table:
                     var table = (element as Table);
-                    foreach (var column in table.Columns)
+                    foreach (var column in table!.Columns)
                     {
                         TraversElement(column, type, handler);
                     }

ZeroLevel/Services/DOM/DSL/Model/TEnvironment.cs

@@ -7,10 +7,10 @@ namespace DOM.DSL.Model
     public sealed class TEnvironment
     {
         public int Delay { get; set; } = 0;
-        public string FileName { get; set; } = null;
+        public string FileName { get; set; } = null!;
-        public Encoding Encoding { get; set; } = null;
+        public Encoding Encoding { get; set; } = null!;
-        public string ContractName { get; set; } = null;
+        public string ContractName { get; set; } = null!;
-        public string SubscriptionName { get; set; } = null;
+        public string SubscriptionName { get; set; } = null!;
         public Guid SubscriptionId { get; set; } = Guid.Empty;
         public IDictionary<string, object> CustomVariables { get; }
 

ZeroLevel/Services/DOM/DSL/Model/TFlowRules.cs

@@ -353,7 +353,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "special": // Using a hardcoded table conversion
-                                        //TablePrefix = TablePostfix = null;
+                                        //TablePrefix = TablePostfix = null!;
                             ColumnsPrefix = ColumnsPostfix = null!;
                             ColumnPrefix = ColumnTemplate = ColumnPostfix = null!;
                             RowPrefix = RowPostfix = null!;
@@ -361,7 +361,7 @@ namespace DOM.DSL.Model
                             // Args: (style, paddings l-t-r-b, maxcellwidth, maxtablewidth)
                             UseSpecialTableBuilder = true;
                             SpecialTableBuilder = SpecialTableBuilderFactory.CreateSpecialTableBuilder(special);
-                            if (SpecialTableBuilder == null) UseSpecialTableBuilder = false;
+                            if (SpecialTableBuilder == null!) UseSpecialTableBuilder = false;
                             break;
                     }
                     break;

ZeroLevel/Services/DOM/DSL/Services/PlainTextTableBuilder.cs

@@ -19,10 +19,10 @@ namespace DOM.DSL.Services
 
             public void FlushRow()
             {
-                if (RowCells != null)
+                if (RowCells != null!)
                 {
                     Data.AppendRow(RowCells);
-                    RowCells = null;
+                    RowCells = null!;
                 }
             }
 

ZeroLevel/Services/DOM/DSL/Services/TContainer.cs

@@ -30,7 +30,7 @@ namespace DOM.DSL.Services
 
             public void Append(object _item)
             {
-                if (_item == null) return;
+                if (_item == null!) return;
                 object item;
                 if (_item is TContainer)
                 {
@@ -40,7 +40,7 @@ namespace DOM.DSL.Services
                 {
                     item = _item;
                 }
-                if (_list == null)
+                if (_list == null!)
                 {
                     _elementType = item.GetType();
                     _list = (IList)Activator.CreateInstance(typeof(List<>).MakeGenericType(_elementType));
@@ -159,7 +159,7 @@ namespace DOM.DSL.Services
         public void MoveToProperty(string propertyName, string propertyIndex)
         {
             if (propertyName.Equals("order", StringComparison.OrdinalIgnoreCase)) { Reset(Index); return; }
-            if (_current == null) return;
+            if (_current == null!) return;
 
             var buff_val = _current;
             var buff_index = Index;
@@ -211,7 +211,7 @@ namespace DOM.DSL.Services
         {
             var buff_val = _current;
             var buff_index = Index;
-            TContainer[] args = null;
+            TContainer[] args = null!;
             try
             {
                 switch (GetFunctionType(functionName))
@@ -242,7 +242,7 @@ namespace DOM.DSL.Services
                 _current = buff_val;
                 Index = buff_index;
             }
-            if (args != null)
+            if (args != null!)
             {
                 foreach (var a in args)
                     _factory.Release(a);
@@ -253,7 +253,7 @@ namespace DOM.DSL.Services
 
         public T As<T>()
         {
-            if (_current == null) return default(T);
+            if (_current == null!) return default(T)!;
             if (_current is T) return (T)_current;
             var type = typeof(T);
             if (_current is string)
@@ -267,13 +267,13 @@ namespace DOM.DSL.Services
             catch (Exception ex)
             {
                 Log.SystemWarning($"[DOM.TContainer] Fault cast current value from type '{_current?.GetType()?.FullName ?? string.Empty}' to type '{type.FullName}'. {ex.ToString()}");
-                return default(T);
+                return default(T)!;
             }
         }
 
         public object As(Type type)
         {
-            if (_current == null) return TypeHelpers.CreateDefaultState(type);
+            if (_current == null!) return TypeHelpers.CreateDefaultState(type);
             if (_current.GetType().IsAssignableFrom(type)) return _current;
             if (_current is string)
             {
@@ -927,7 +927,7 @@ namespace DOM.DSL.Services
                     break;
             }
 
-            if (enumerable != null)
+            if (enumerable != null!)
             {
                 int index;
                 if (int.TryParse(propertyIndex, out index))
@@ -1336,7 +1336,7 @@ namespace DOM.DSL.Services
             }
             else
             {
-                Reset(null);
+                Reset(null!);
             }
         }
 
@@ -1388,7 +1388,7 @@ namespace DOM.DSL.Services
 
         private void ApplyStringFunction(string function, TContainer[] args)
         {
-            if (_current == null)
+            if (_current == null!)
             {
                 args = null!;
                 return;
@@ -1774,7 +1774,7 @@ namespace DOM.DSL.Services
 
         private void ApplyExtractionFunction(string function, Func<TContainer, TContainer[]> args_getter, out TContainer[] args)
         {
-            if (_current == null)
+            if (_current == null!)
             {
                 if (function.Equals("append", StringComparison.OrdinalIgnoreCase))
                 {
@@ -1806,7 +1806,7 @@ namespace DOM.DSL.Services
             }
             if (function.Equals("where", StringComparison.OrdinalIgnoreCase))
             {
-                if (args_getter != null)
+                if (args_getter != null!)
                 {
                     if (IsEnumerable)
                     {
@@ -1814,10 +1814,10 @@ namespace DOM.DSL.Services
                         int index = 0;
                         foreach (var i in ((IEnumerable)_current))
                         {
-                            if (i == null) continue;
+                            if (i == null!) continue;
                             var container = _factory.Get(i, index);
                             var conditions = args_getter(container);
-                            if (conditions != null)
+                            if (conditions != null!)
                             {
                                 bool success = conditions.Any();
                                 foreach (var c in conditions)
@@ -1836,7 +1836,7 @@ namespace DOM.DSL.Services
                         Reset(list.Complete());
                     }
                 }
-                args = null;
+                args = null!;
                 return;
             }
             else
@@ -1856,7 +1856,7 @@ namespace DOM.DSL.Services
                             {
                                 _render.BufferDictionary[key] = this._current;
                             }
-                            Reset(null);
+                            Reset(null!);
                         }
                         break;
 
@@ -1967,7 +1967,7 @@ namespace DOM.DSL.Services
                                     var list = new TDList();
                                     foreach (var i in ((IEnumerable)_current))
                                     {
-                                        if (i == null) continue;
+                                        if (i == null!) continue;
                                         var container = _factory.Get(i);
                                         container.MoveToProperty(property, property_index!);
                                         list.Append(container.Current);
@@ -1998,7 +1998,7 @@ namespace DOM.DSL.Services
                                     var list = new TDList();
                                     foreach (var i in ((IEnumerable)_current))
                                     {
-                                        if (i == null) continue;
+                                        if (i == null!) continue;
                                         var container = _factory.Get(i);
                                         switch (functionType)
                                         {
@@ -2062,7 +2062,7 @@ namespace DOM.DSL.Services
 
                     case "tonum":
                     case "tonumber":
-                        if (_current != null)
+                        if (_current != null!)
                         {
                             var buf = _current.ToString();
                             int num;
@@ -2081,7 +2081,7 @@ namespace DOM.DSL.Services
                         if (_current is List<TContainer>)
                         {
                             var list = _current as List<TContainer>;
-                            if (list == null)
+                            if (list == null!)
                             {
                                 _current = new List<TContainer>();
                                 list = _current as List<TContainer>;
@@ -2455,7 +2455,7 @@ namespace DOM.DSL.Services
 
         private void ChangeDateTime(TContainer value, ChangeDateTimeType type)
         {
-            if (_current == null) return;
+            if (_current == null!) return;
             if (_current is DateTime)
             {
                 var dt = (DateTime)_current;
@@ -2498,7 +2498,7 @@ namespace DOM.DSL.Services
 
         public bool Any(TContainer[] set = null!, bool ignoreCase = true)
         {
-            if (_current == null) return false;
+            if (_current == null!) return false;
             if (set?.Any() ?? false)
             {
                 if (_current is IEnumerable && false == (_current is string))
@@ -2525,7 +2525,7 @@ namespace DOM.DSL.Services
 
         public bool Contains(TContainer[] set, bool ignoreCase)
         {
-            if (_current == null) return false;
+            if (_current == null!) return false;
             if (set == null || set?.Length == 0) return false;
             if (_current is IEnumerable && false == (_current is string))
             {
@@ -2564,8 +2564,8 @@ namespace DOM.DSL.Services
 
         public bool NoContains(TContainer[] test, bool ignoreCase)
         {
-            if (_current == null) return false;
+            if (_current == null!) return false;
-            if (_current == null) return false;
+            if (_current == null!) return false;
             if (_current is IEnumerable && false == (_current is string))
             {
                 foreach (var c in (IEnumerable)_current)
@@ -2588,43 +2588,43 @@ namespace DOM.DSL.Services
 
         public bool IsEmpty()
         {
-            if (_current == null) return true;
+            if (_current == null!) return true;
             return String.IsNullOrWhiteSpace(_current.ToString());
         }
 
         public bool Is(TContainer test, bool ignoreCase)
         {
-            if (_current == null) return test.Current == null;
+            if (_current == null!) return test.Current == null!;
             return CompareWith(test, ignoreCase) == 0;
         }
 
         public bool IsNot(TContainer test, bool ignoreCase)
         {
-            if (_current == null) return test.Current != null;
+            if (_current == null!) return test.Current != null!;
             return CompareWith(test, ignoreCase) != 0;
         }
 
         public bool LessThan(TContainer test, bool ignoreCase)
         {
-            if (_current == null) return false;
+            if (_current == null!) return false;
             return CompareWith(test, ignoreCase) < 0;
         }
 
         public bool MoreThan(TContainer test, bool ignoreCase)
         {
-            if (_current == null) return false;
+            if (_current == null!) return false;
             return CompareWith(test, ignoreCase) > 0;
         }
 
         public bool LessOrEq(TContainer test, bool ignoreCase)
         {
-            if (_current == null) return false;
+            if (_current == null!) return false;
             return CompareWith(test, ignoreCase) <= 0;
         }
 
         public bool MoreOrEq(TContainer test, bool ignoreCase)
         {
-            if (_current == null) return false;
+            if (_current == null!) return false;
             return CompareWith(test, ignoreCase) >= 0;
         }
 
@@ -2734,7 +2734,7 @@ namespace DOM.DSL.Services
         private static string FormattedDateTime(DateTime dt, string format = null!, string culture = null!)
         {
             CultureInfo ci;
-            if (culture != null)
+            if (culture != null!)
             {
                 try
                 {
@@ -2764,7 +2764,7 @@ namespace DOM.DSL.Services
 
         public override string ToString()
         {
-            if (_current == null) return string.Empty;
+            if (_current == null!) return string.Empty;
 
             if (_current is string) return (string)_current;
             else if (_current is DateTime) return FormattedDateTime((DateTime)_current);

ZeroLevel/Services/DOM/DSL/Services/TContainerFactory.cs

@@ -37,7 +37,7 @@ namespace DOM.DSL.Services
 
         internal void Release(TContainer container)
         {
-            if (container != null)
+            if (container != null!)
             {
                 Interlocked.Increment(ref _release_count);
                 _pool.Return(container);

ZeroLevel/Services/DOM/DSL/Services/TContentToStringConverter.cs

@@ -22,7 +22,7 @@ namespace DOM.DSL.Services
             _render = render;
             _transformRules = rules;
             _specialTableBuilder = rules.SpecialTableBuilder;
-            _useSpecialTableBuilder = rules.UseSpecialTableBuilder && rules.SpecialTableBuilder != null;
+            _useSpecialTableBuilder = rules.UseSpecialTableBuilder && rules.SpecialTableBuilder != null!;
 
             _builder = new StringBuilder();
         }
@@ -58,15 +58,15 @@ namespace DOM.DSL.Services
         public void ReadAudio(Audio audio, int order)
         {
             _render.Counter.IncAudioId();
-            if (_transformRules.AudioPrefix != null)
+            if (_transformRules.AudioPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.AudioPrefix, audio, order));
             }
-            if (_transformRules.AudioTemplate != null)
+            if (_transformRules.AudioTemplate != null!)
             {
                 WriteText(Resolve(_transformRules.AudioTemplate, audio, order));
             }
-            if (_transformRules.AudioPostfix != null)
+            if (_transformRules.AudioPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.AudioPostfix, audio, order));
             }
@@ -75,15 +75,15 @@ namespace DOM.DSL.Services
         public void ReadColumn(Table table, Column column, int order)
         {
             _render.Counter.IncColumnId();
-            if (_transformRules.ColumnPrefix != null)
+            if (_transformRules.ColumnPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.ColumnPrefix, column, order));
             }
-            if (_transformRules.ColumnTemplate != null)
+            if (_transformRules.ColumnTemplate != null!)
             {
                 WriteText(Resolve(_transformRules.ColumnTemplate, column, order));
             }
-            if (_transformRules.ColumnPostfix != null)
+            if (_transformRules.ColumnPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.ColumnPostfix, column, order));
             }
@@ -92,15 +92,15 @@ namespace DOM.DSL.Services
         public void ReadForm(FormContent form)
         {
             _render.Counter.IncFormId();
-            if (_transformRules.FormPrefix != null)
+            if (_transformRules.FormPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.FormPrefix, form, 0));
             }
-            if (_transformRules.FormTemplate != null)
+            if (_transformRules.FormTemplate != null!)
             {
                 WriteText(Resolve(_transformRules.FormTemplate, form, 0));
             }
-            if (_transformRules.FormPostfix != null)
+            if (_transformRules.FormPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.FormPostfix, form, 0));
             }
@@ -109,15 +109,15 @@ namespace DOM.DSL.Services
         public void ReadImage(Image image, int order)
         {
             _render.Counter.IncImageId();
-            if (_transformRules.ImagePrefix != null)
+            if (_transformRules.ImagePrefix != null!)
             {
                 WriteText(Resolve(_transformRules.ImagePrefix, image, order));
             }
-            if (_transformRules.ImageTemplate != null)
+            if (_transformRules.ImageTemplate != null!)
             {
                 WriteText(Resolve(_transformRules.ImageTemplate, image, order));
             }
-            if (_transformRules.ImagePostfix != null)
+            if (_transformRules.ImagePostfix != null!)
             {
                 WriteText(Resolve(_transformRules.ImagePostfix, image, order));
             }
@@ -126,15 +126,15 @@ namespace DOM.DSL.Services
         public void ReadLink(Link link, int order)
         {
             _render.Counter.IncLinkId();
-            if (_transformRules.LinkPrefix != null)
+            if (_transformRules.LinkPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.LinkPrefix, link, order));
             }
-            if (_transformRules.LinkTemplate != null)
+            if (_transformRules.LinkTemplate != null!)
             {
                 WriteText(Resolve(_transformRules.LinkTemplate, link, order));
             }
-            if (_transformRules.LinkPostfix != null)
+            if (_transformRules.LinkPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.LinkPostfix, link, order));
             }
@@ -143,15 +143,15 @@ namespace DOM.DSL.Services
         public void ReadQuote(Quote quote)
         {
             _render.Counter.IncQuoteId();
-            if (_transformRules.QuotePrefix != null)
+            if (_transformRules.QuotePrefix != null!)
             {
                 WriteText(Resolve(_transformRules.QuotePrefix, quote, 0));
             }
-            if (_transformRules.QuoteTemplate != null)
+            if (_transformRules.QuoteTemplate != null!)
             {
                 WriteText(Resolve(_transformRules.QuoteTemplate, quote, 0));
             }
-            if (_transformRules.QuotePostfix != null)
+            if (_transformRules.QuotePostfix != null!)
             {
                 WriteText(Resolve(_transformRules.QuotePostfix, quote, 0));
             }
@@ -160,15 +160,15 @@ namespace DOM.DSL.Services
         public void ReadText(Text text)
         {
             _render.Counter.IncTextId();
-            if (_transformRules.TextPrefix != null)
+            if (_transformRules.TextPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.TextPrefix, text, 0));
             }
-            if (_transformRules.TextTemplate != null)
+            if (_transformRules.TextTemplate != null!)
             {
                 WriteText(Resolve(_transformRules.TextTemplate, text, 0));
             }
-            if (_transformRules.TextPostfix != null)
+            if (_transformRules.TextPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.TextPostfix, text, 0));
             }
@@ -177,15 +177,15 @@ namespace DOM.DSL.Services
         public void ReadVideo(Video video, int order)
         {
             _render.Counter.IncVideoId();
-            if (_transformRules.VideoPrefix != null)
+            if (_transformRules.VideoPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.VideoPrefix, video, order));
             }
-            if (_transformRules.VideoTemplate != null)
+            if (_transformRules.VideoTemplate != null!)
             {
                 WriteText(Resolve(_transformRules.VideoTemplate, video, order));
             }
-            if (_transformRules.VideoPostfix != null)
+            if (_transformRules.VideoPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.VideoPostfix, video, order));
             }
@@ -198,7 +198,7 @@ namespace DOM.DSL.Services
         public void EnterParagraph(Paragraph paragraph)
         {
             _render.Counter.IncParagraphId();
-            if (_transformRules.ParagraphPrefix != null)
+            if (_transformRules.ParagraphPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.ParagraphPrefix, paragraph, _render.Counter.ParagraphId));
             }
@@ -206,7 +206,7 @@ namespace DOM.DSL.Services
 
         public void LeaveParagraph(Paragraph paragraph)
         {
-            if (_transformRules.ParagraphPostfix != null)
+            if (_transformRules.ParagraphPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.ParagraphPostfix, paragraph, _render.Counter.ParagraphId));
             }
@@ -215,7 +215,7 @@ namespace DOM.DSL.Services
         public void EnterSection(Section section)
         {
             _render.Counter.IncSectionId();
-            if (_transformRules.SectionPrefix != null)
+            if (_transformRules.SectionPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.SectionPrefix, section, _render.Counter.SectionId));
             }
@@ -223,7 +223,7 @@ namespace DOM.DSL.Services
 
         public void LeaveSection(Section section)
         {
-            if (_transformRules.SectionPostfix != null)
+            if (_transformRules.SectionPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.SectionPostfix, section, _render.Counter.SectionId));
             }
@@ -236,7 +236,7 @@ namespace DOM.DSL.Services
         public void EnterTable(Table table)
         {
             _render.Counter.IncTableId();
-            if (_transformRules.TablePrefix != null)
+            if (_transformRules.TablePrefix != null!)
             {
                 _builder.Append(Resolve(_transformRules.TablePrefix, table, _render.Counter.TableId));
             }
@@ -249,7 +249,7 @@ namespace DOM.DSL.Services
 
         public void EnterColumns(Table table)
         {
-            if (_useSpecialTableBuilder == false && _transformRules.ColumnsPrefix != null)
+            if (_useSpecialTableBuilder == false && _transformRules.ColumnsPrefix != null!)
             {
                 _builder.Append(Resolve(_transformRules.ColumnsPrefix, table.Columns, 0));
             }
@@ -262,7 +262,7 @@ namespace DOM.DSL.Services
             {
                 _specialTableBuilder.EnterRow(row.Cells.Count);
             }
-            else if (_transformRules.RowPrefix != null)
+            else if (_transformRules.RowPrefix != null!)
             {
                 _builder.Append(Resolve(_transformRules.RowPrefix, row, order));
             }
@@ -277,11 +277,11 @@ namespace DOM.DSL.Services
             }
             else
             {
-                if (order == 0 && _transformRules.FirstRowCellPrefix != null)
+                if (order == 0 && _transformRules.FirstRowCellPrefix != null!)
                 {
                     _builder.Append(Resolve(_transformRules.FirstRowCellPrefix, cell, order));
                 }
-                else if (_transformRules.CellPrefix != null)
+                else if (_transformRules.CellPrefix != null!)
                 {
                     _builder.Append(Resolve(_transformRules.CellPrefix, cell, order));
                 }
@@ -290,7 +290,7 @@ namespace DOM.DSL.Services
 
         public void LeaveColumns(Table table)
         {
-            if (_useSpecialTableBuilder == false && _transformRules.ColumnsPostfix != null)
+            if (_useSpecialTableBuilder == false && _transformRules.ColumnsPostfix != null!)
             {
                 _builder.Append(Resolve(_transformRules.ColumnsPostfix, table.Columns, 0));
             }
@@ -302,7 +302,7 @@ namespace DOM.DSL.Services
             {
                 _specialTableBuilder.LeaveRow();
             }
-            else if (_transformRules.RowPostfix != null)
+            else if (_transformRules.RowPostfix != null!)
             {
                 _builder.Append(Resolve(_transformRules.RowPostfix, row, order));
             }
@@ -316,11 +316,11 @@ namespace DOM.DSL.Services
             }
             else
             {
-                if (order == 0 && _transformRules.FirstRowCellPostfix != null)
+                if (order == 0 && _transformRules.FirstRowCellPostfix != null!)
                 {
                     _builder.Append(Resolve(_transformRules.FirstRowCellPostfix, cell, order));
                 }
-                else if (_transformRules.CellPostfix != null)
+                else if (_transformRules.CellPostfix != null!)
                 {
                     _builder.Append(Resolve(_transformRules.CellPostfix, cell, order));
                 }
@@ -333,7 +333,7 @@ namespace DOM.DSL.Services
             {
                 _specialTableBuilder.FlushTable(_builder);
             }
-            if (_transformRules.TablePostfix != null)
+            if (_transformRules.TablePostfix != null!)
             {
                 _builder.Append(Resolve(_transformRules.TablePostfix, table, _render.Counter.TableId));
             }
@@ -346,7 +346,7 @@ namespace DOM.DSL.Services
         public void EnterList(List list)
         {
             _render.Counter.IncListId();
-            if (_transformRules.ListPrefix != null)
+            if (_transformRules.ListPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.ListPrefix, list, 0));
             }
@@ -355,7 +355,7 @@ namespace DOM.DSL.Services
         public void EnterListItem(List list, IContentElement item, int order)
         {
             _render.Counter.IncListItemId();
-            if (_transformRules.ListItemPrefix != null)
+            if (_transformRules.ListItemPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.ListItemPrefix, item, order));
             }
@@ -363,7 +363,7 @@ namespace DOM.DSL.Services
 
         public void LeaveList(List list)
         {
-            if (_transformRules.ListPostfix != null)
+            if (_transformRules.ListPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.ListPostfix, list, 0));
             }
@@ -371,7 +371,7 @@ namespace DOM.DSL.Services
 
         public void LeaveListItem(List list, IContentElement item, int order)
         {
-            if (_transformRules.ListItemPostfix != null)
+            if (_transformRules.ListItemPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.ListItemPostfix, item, order));
             }
@@ -384,7 +384,7 @@ namespace DOM.DSL.Services
         public void EnterAudioplayer(Audioplayer player)
         {
             _render.Counter.IncAudioplayerId();
-            if (_transformRules.AudioplayerPrefix != null)
+            if (_transformRules.AudioplayerPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.AudioplayerPrefix, player, 0));
             }
@@ -393,7 +393,7 @@ namespace DOM.DSL.Services
         public void EnterGallery(Gallery gallery)
         {
             _render.Counter.IncGalleryId();
-            if (_transformRules.GalleryPrefix != null)
+            if (_transformRules.GalleryPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.GalleryPrefix, gallery, 0));
             }
@@ -402,7 +402,7 @@ namespace DOM.DSL.Services
         public void EnterVideoplayer(Videoplayer player)
         {
             _render.Counter.IncVideoplayerId();
-            if (_transformRules.VideoplayerPrefix != null)
+            if (_transformRules.VideoplayerPrefix != null!)
             {
                 WriteText(Resolve(_transformRules.VideoplayerPrefix, player, 0));
             }
@@ -410,7 +410,7 @@ namespace DOM.DSL.Services
 
         public void LeaveAudioplayer(Audioplayer player)
         {
-            if (_transformRules.AudioplayerPostfix != null)
+            if (_transformRules.AudioplayerPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.AudioplayerPostfix, player, 0));
             }
@@ -418,7 +418,7 @@ namespace DOM.DSL.Services
 
         public void LeaveGallery(Gallery gallery)
         {
-            if (_transformRules.GalleryPostfix != null)
+            if (_transformRules.GalleryPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.GalleryPostfix, gallery, 0));
             }
@@ -426,7 +426,7 @@ namespace DOM.DSL.Services
 
         public void LeaveVideoplayer(Videoplayer player)
         {
-            if (_transformRules.VideoplayerPostfix != null)
+            if (_transformRules.VideoplayerPostfix != null!)
             {
                 WriteText(Resolve(_transformRules.VideoplayerPostfix, player, 0));
             }

ZeroLevel/Services/DOM/DSL/Services/TRender.cs

@@ -21,7 +21,7 @@ namespace DOM.DSL.Services
                 _blocks.Add(name, tokens);
             else
             {
-                _blocks[name] = null;
+                _blocks[name] = null!;
                 _blocks[name] = tokens;
             }
         }
@@ -157,7 +157,7 @@ namespace DOM.DSL.Services
                         {
                             var block = new TBlockToken(_blocks.Get(token.NextToken.AsPropertyToken().PropertyName));
                             var result = ResolveBlockToken(block, self);
-                            container = Factory.Get(result.Where(c => c.Current != null).Select(c => c.Current).ToList());
+                            container = Factory.Get(result.Where(c => c.Current != null!).Select(c => c.Current).ToList());
                             foreach (var c in result)
                                 Factory.Release(c);
                         }
@@ -165,7 +165,7 @@ namespace DOM.DSL.Services
                     }
             }
 
-            if (container == null) container = Factory.Get(null!);
+            if (container == null!) container = Factory.Get(null!);
 
             if (token.NextToken is TPropertyToken)
             {
@@ -255,7 +255,7 @@ namespace DOM.DSL.Services
                         {
                             var ls = self_parent == null ? null : Factory.Get(self_parent.Current, self_parent.Index);
                             result = ResolveSimpleBlockToken(blockToken, ls!);
-                            Factory.Release(ls);
+                            Factory.Release(ls!);
                         }
                         else
                         {
@@ -268,7 +268,7 @@ namespace DOM.DSL.Services
                         var list = new List<TContainer>();
                         TContainer self_container = null!;
                         Resolve(blockToken.Condition, c => self_container = c, false, self_parent);
-                        if (self_container != null)
+                        if (self_container != null!)
                         {
                             if (self_container.IsEnumerable)
                             {
@@ -319,7 +319,7 @@ namespace DOM.DSL.Services
                 {
                     var function = token.AsElementToken()?.NextToken?.AsFunctionToken();
                     var elementName = token.AsElementToken()?.ElementName;
-                    if (elementName != null)
+                    if (elementName != null!)
                     {
                         var functionName = function?.FunctionName ?? string.Empty;
                         var rule_token = function?.FunctionArgs == null ?

ZeroLevel/Services/DOM/DSL/TEngine.cs

@@ -36,11 +36,11 @@ namespace DOM.DSL
 
         public static string Apply(Document document, IEnumerable<TToken> tokens, TEnvironment environment, bool ignore_fault = true)
         {
-            if (document == null)
+            if (document == null!)
             {
                 throw new ArgumentNullException(nameof(document));
             }
-            if (tokens == null)
+            if (tokens == null!)
             {
                 throw new ArgumentNullException(nameof(tokens));
             }

ZeroLevel/Services/DOM/DSL/Tokens/TElementToken.cs

@@ -21,7 +21,7 @@
             return new TElementToken
             {
                 ElementName = this.ElementName,
-                NextToken = this.NextToken?.Clone()
+                NextToken = this.NextToken?.Clone()!
             };
         }
 
@@ -30,7 +30,7 @@
             return new TElementToken
             {
                 ElementName = this.ElementName,
-                NextToken = null
+                NextToken = null!
             };
         }
     }

ZeroLevel/Services/DOM/DSL/Tokens/TFunctionToken.cs

@@ -16,7 +16,7 @@ namespace DOM.DSL.Tokens
             {
                 FunctionArgs = FunctionArgs.Select(a => a.Clone()).ToArray(),
                 FunctionName = this.FunctionName,
-                NextToken = this.NextToken?.Clone()
+                NextToken = this.NextToken?.Clone()!
             };
         }
 
@@ -26,7 +26,7 @@ namespace DOM.DSL.Tokens
             {
                 FunctionArgs = FunctionArgs.Select(a => a.Clone()).ToArray(),
                 FunctionName = this.FunctionName,
-                NextToken = null
+                NextToken = null!
             };
         }
     }

ZeroLevel/Services/DOM/DSL/Tokens/TPropertyToken.cs

@@ -13,7 +13,7 @@
             {
                 PropertyIndex = this.PropertyIndex,
                 PropertyName = this.PropertyName,
-                NextToken = this.NextToken?.Clone()
+                NextToken = this.NextToken?.Clone()!
             };
         }
 
@@ -23,7 +23,7 @@
             {
                 PropertyIndex = this.PropertyIndex,
                 PropertyName = this.PropertyName,
-                NextToken = null
+                NextToken = null!
             };
         }
     }

ZeroLevel/Services/DOM/DSL/Tokens/TSystemToken.cs

@@ -11,7 +11,7 @@
             return new TSystemToken
             {
                 Command = this.Command,
-                Arg = this.Arg?.Clone()
+                Arg = this.Arg?.Clone()!
             };
         }
 

ZeroLevel/Services/DOM/DSL/Tokens/TToken.cs

@@ -15,16 +15,16 @@ namespace DOM.DSL.Tokens
         /// <returns></returns>
         public abstract TToken CloneLocal();
 
-        public TElementToken AsElementToken() => this as TElementToken;
+        public TElementToken AsElementToken() => (this as TElementToken)!;
 
-        public TFunctionToken AsFunctionToken() => this as TFunctionToken;
+        public TFunctionToken AsFunctionToken() => (this as TFunctionToken)!;
 
-        public TTextToken AsTextToken() => this as TTextToken;
+        public TTextToken AsTextToken() => (this as TTextToken)!;
 
-        public TBlockToken AsBlockToken() => this as TBlockToken;
+        public TBlockToken AsBlockToken() => (this as TBlockToken)!;
 
-        public TPropertyToken AsPropertyToken() => this as TPropertyToken;
+        public TPropertyToken AsPropertyToken() => (this as TPropertyToken)!;
 
-        public TSystemToken AsSystemToken() => this as TSystemToken;
+        public TSystemToken AsSystemToken() => (this as TSystemToken)!;
     }
 }

ZeroLevel/Services/DOM/Model/AttachContent.cs

@@ -57,7 +57,7 @@ namespace ZeroLevel.DocumentObjectModel
 
         public T Read<T>()
         {
-            if (this.Payload == null || this.Payload.Length == 0) return default(T);
+            if (this.Payload == null || this.Payload.Length == 0) return default(T)!;
             return MessageSerializer.DeserializeCompatible<T>(this.Payload);
         }
 

ZeroLevel/Services/DOM/Model/Category.cs

@@ -14,7 +14,7 @@ namespace ZeroLevel.DocumentObjectModel
         {
         }
 
-        public Category(string title, string code, string direction_code, string description = null,
+        public Category(string title, string code, string direction_code, string description = null!,
             bool is_system = false)
         {
             this.Title = title;
@@ -104,7 +104,7 @@ namespace ZeroLevel.DocumentObjectModel
 
         public bool Equals(Category other)
         {
-            if (other == null) return false;
+            if (other == null!) return false;
             if (string.Compare(this.Title, other.Title, StringComparison.Ordinal) != 0) return false;
             if (string.Compare(this.Code, other.Code, StringComparison.Ordinal) != 0) return false;
             if (string.Compare(this.Description, other.Description, StringComparison.Ordinal) != 0) return false;
@@ -119,7 +119,7 @@ namespace ZeroLevel.DocumentObjectModel
 
         public override bool Equals(object obj)
         {
-            return this.Equals(obj as Category);
+            return this.Equals((obj as Category)!);
         }
 
         public override int GetHashCode()

ZeroLevel/Services/DOM/Model/Header.cs

@@ -77,7 +77,7 @@ namespace ZeroLevel.DocumentObjectModel
 
         public bool Equals(Header other)
         {
-            if (other == null) return false;
+            if (other == null!) return false;
             if (string.Compare(this.Name, other.Name, StringComparison.Ordinal) != 0) return false;
             if (string.Compare(this.Value, other.Value, StringComparison.Ordinal) != 0) return false;
             if (string.Compare(this.Type, other.Type, StringComparison.Ordinal) != 0) return false;
@@ -91,7 +91,7 @@ namespace ZeroLevel.DocumentObjectModel
 
         public override bool Equals(object obj)
         {
-            return this.Equals(obj as Header);
+            return this.Equals((obj as Header)!);
         }
 
         public override int GetHashCode()

ZeroLevel/Services/DOM/Services/ContentBuilder.cs

@@ -16,7 +16,7 @@ namespace DOM.Services
 
         public ContentBuilder(Document document)
         {
-            if (document == null)
+            if (document == null!)
             {
                 throw new ArgumentNullException(nameof(document));
             }
@@ -318,7 +318,7 @@ namespace DOM.Services
             {
                 RaiseIncorrectTypeException(section.Type, ContentElementType.Section);
             }
-            _content.Sections.Add(section as Section);
+            _content.Sections.Add((section as Section)!);
         }
 
         public void EnterParagraph()
@@ -482,7 +482,7 @@ namespace DOM.Services
 
         public void WriteColumn(Column column)
         {
-            if (column == null)
+            if (column == null!)
             {
                 throw new ArgumentNullException(nameof(column));
             }
@@ -491,7 +491,7 @@ namespace DOM.Services
 
         public void WriteText(Text text)
         {
-            if (text == null)
+            if (text == null!)
             {
                 throw new ArgumentNullException(nameof(text));
             }
@@ -515,7 +515,7 @@ namespace DOM.Services
 
         public void WriteQuote(Quote quote)
         {
-            if (quote == null)
+            if (quote == null!)
             {
                 throw new ArgumentNullException(nameof(quote));
             }
@@ -529,7 +529,7 @@ namespace DOM.Services
 
         public void WriteLink(Link link)
         {
-            if (link == null)
+            if (link == null!)
             {
                 throw new ArgumentNullException(nameof(link));
             }
@@ -543,7 +543,7 @@ namespace DOM.Services
 
         public void WriteForm(FormContent form)
         {
-            if (form == null)
+            if (form == null!)
             {
                 throw new ArgumentNullException(nameof(form));
             }
@@ -552,7 +552,7 @@ namespace DOM.Services
 
         public void WriteImage(Image image)
         {
-            if (image == null)
+            if (image == null!)
             {
                 throw new ArgumentNullException(nameof(image));
             }
@@ -561,7 +561,7 @@ namespace DOM.Services
 
         public void WriteAudio(Audio audio)
         {
-            if (audio == null)
+            if (audio == null!)
             {
                 throw new ArgumentNullException(nameof(audio));
             }
@@ -570,7 +570,7 @@ namespace DOM.Services
 
         public void WriteVideo(Video video)
         {
-            if (video == null)
+            if (video == null!)
             {
                 throw new ArgumentNullException(nameof(video));
             }

ZeroLevel/Services/DOM/Services/DocumentContentReader.cs

@@ -52,7 +52,7 @@ namespace DOM.Services
                 case ContentElementType.Content:
                     {
                         var content = (element as FlowContent);
-                        if (content != null)
+                        if (content != null!)
                         {
                             for (int i = 0; i < content.Sections.Count; i++)
                             {
@@ -64,7 +64,7 @@ namespace DOM.Services
 
                 case ContentElementType.Section:
                     var section = (element as Section);
-                    if (section != null)
+                    if (section != null!)
                     {
                         reader.EnterSection(section);
                         for (int i = 0; i < section.Parts.Count; i++)
@@ -77,7 +77,7 @@ namespace DOM.Services
 
                 case ContentElementType.Paragraph:
                     var paragraph = (element as Paragraph);
-                    if (paragraph != null)
+                    if (paragraph != null!)
                     {
                         reader.EnterParagraph(paragraph);
                         for (int i = 0; i < paragraph.Parts.Count; i++)
@@ -90,7 +90,7 @@ namespace DOM.Services
 
                 case ContentElementType.List:
                     var list = (element as List);
-                    if (list != null)
+                    if (list != null!)
                     {
                         reader.EnterList(list);
                         for (int i = 0; i < list.Items.Count; i++)
@@ -105,7 +105,7 @@ namespace DOM.Services
 
                 case ContentElementType.Gallery:
                     var gallery = (element as Gallery);
-                    if (gallery != null)
+                    if (gallery != null!)
                     {
                         reader.EnterGallery(gallery);
                         for (int i = 0; i < gallery.Images.Count; i++)
@@ -118,7 +118,7 @@ namespace DOM.Services
 
                 case ContentElementType.Audioplayer:
                     var audioplayer = (element as Audioplayer);
-                    if (audioplayer != null)
+                    if (audioplayer != null!)
                     {
                         reader.EnterAudioplayer(audioplayer);
                         for (int i = 0; i < audioplayer.Tracks.Count; i++)
@@ -131,7 +131,7 @@ namespace DOM.Services
 
                 case ContentElementType.Videoplayer:
                     var videoplayer = (element as Videoplayer);
-                    if (videoplayer != null)
+                    if (videoplayer != null!)
                     {
                         reader.EnterVideoplayer(videoplayer);
                         for (int i = 0; i < videoplayer.Playlist.Count; i++)
@@ -144,7 +144,7 @@ namespace DOM.Services
 
                 case ContentElementType.Table:
                     var table = (element as Table);
-                    if (table != null)
+                    if (table != null!)
                     {
                         reader.EnterTable(table);
                         reader.EnterColumns(table);

ZeroLevel/Services/DependencyInjection/Container.cs

@@ -15,7 +15,7 @@ namespace ZeroLevel.DependencyInjection
 
         private static object Activate(Type type, object[] args)
         {
-            if (type == null) return null!;
+            if (type == null!) return null!;
             var flags = BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public;
             CultureInfo culture = null!; // use InvariantCulture or other if you prefer
             return Activator.CreateInstance(type, flags, null, args, culture);
@@ -157,7 +157,7 @@ namespace ZeroLevel.DependencyInjection
             Type instanceType = resolveType.GenericCachee[genericType];
             if (resolveType.IsShared)
             {
-                if (resolveType.GenericInstanceCachee == null)
+                if (resolveType.GenericInstanceCachee == null!)
                 {
                     resolveType.GenericInstanceCachee = new Dictionary<Type, object>();
                 }
@@ -188,7 +188,7 @@ namespace ZeroLevel.DependencyInjection
         private static IEnumerable<PropertyInfo> CollectResolvingProperties(Type type)
         {
             return type.GetProperties(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy).
-                Where(p => p.GetCustomAttribute<ResolveAttribute>() != null);
+                Where(p => p.GetCustomAttribute<ResolveAttribute>() != null!);
         }
 
         /// <summary>
@@ -199,7 +199,7 @@ namespace ZeroLevel.DependencyInjection
         private static IEnumerable<FieldInfo> CollectResolvingFields(Type type)
         {
             return type.GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy).
-                Where(p => p.GetCustomAttribute<ResolveAttribute>() != null);
+                Where(p => p.GetCustomAttribute<ResolveAttribute>() != null!);
         }
 
         /// <summary>
@@ -212,7 +212,7 @@ namespace ZeroLevel.DependencyInjection
         private ResolveTypeInfo FindResolving(Type type, string resolveName, Type contractType)
         {
             HashSet<Type> contract_candidates = new HashSet<Type>();
-            if (contractType != null)
+            if (contractType != null!)
             {
                 if (contractType.IsInterface)
                     contract_candidates.Add(contractType);
@@ -321,8 +321,8 @@ namespace ZeroLevel.DependencyInjection
         /// <returns>Instance</returns>
         private object MakeInstance(Type type, object[] args)
         {
-            ConstructorInfo constructor = null;
+            ConstructorInfo constructor = null!;
-            object[] parameters = null;
+            object[] parameters = null!;
             foreach (var ctor in GetConstructors(type))
             {
                 if (ctor.IsMatch(args, out parameters))
@@ -339,7 +339,7 @@ namespace ZeroLevel.DependencyInjection
             {
                 return constructor.Invoke(parameters);
                 /*var flags = BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public;
-                CultureInfo culture = null; // use InvariantCulture or other if you prefer
+                CultureInfo culture = null!; // use InvariantCulture or other if you prefer
                 return Activator.CreateInstance(type, flags, null, args, culture);*/
             }
         }
@@ -430,7 +430,7 @@ namespace ZeroLevel.DependencyInjection
                 ImplementationType = typeof(TImplementation),
                 IsDefault = string.IsNullOrWhiteSpace(resolveName),
                 IsShared = false,
-                ResolveKey = resolveName?.Trim()
+                ResolveKey = resolveName?.Trim()!
             };
             Register(typeof(TContract), resolveType);
         }
@@ -442,7 +442,7 @@ namespace ZeroLevel.DependencyInjection
                 ImplementationType = typeof(TImplementation),
                 IsDefault = string.IsNullOrWhiteSpace(resolveName),
                 IsShared = shared,
-                ResolveKey = resolveName?.Trim()
+                ResolveKey = resolveName?.Trim()!
             };
             Register(typeof(TContract), resolveType);
         }
@@ -466,7 +466,7 @@ namespace ZeroLevel.DependencyInjection
                 ImplementationType = implementationType,
                 IsDefault = string.IsNullOrWhiteSpace(resolveName),
                 IsShared = false,
-                ResolveKey = resolveName?.Trim()
+                ResolveKey = resolveName?.Trim()!
             };
             Register(contractType, resolveType);
         }
@@ -490,7 +490,7 @@ namespace ZeroLevel.DependencyInjection
                 ImplementationType = implementationType,
                 IsDefault = string.IsNullOrWhiteSpace(resolveName),
                 IsShared = shared,
-                ResolveKey = resolveName?.Trim()
+                ResolveKey = resolveName?.Trim()!
             };
             Register(contractType, resolveType);
         }
@@ -519,7 +519,7 @@ namespace ZeroLevel.DependencyInjection
                 ImplementationType = typeof(TImplementation),
                 IsDefault = string.IsNullOrWhiteSpace(resolveName),
                 IsShared = false,
-                ResolveKey = resolveName?.Trim(),
+                ResolveKey = resolveName?.Trim()!,
                 ConstructorParameters = constructorParameters
             };
             Register(typeof(TContract), resolveType);
@@ -545,7 +545,7 @@ namespace ZeroLevel.DependencyInjection
                 ImplementationType = typeof(TImplementation),
                 IsDefault = string.IsNullOrWhiteSpace(resolveName),
                 IsShared = shared,
-                ResolveKey = resolveName?.Trim(),
+                ResolveKey = resolveName?.Trim()!,
                 ConstructorParameters = constructorParameters
             };
             Register(typeof(TContract), resolveType);
@@ -571,7 +571,7 @@ namespace ZeroLevel.DependencyInjection
                 ImplementationType = implementationType,
                 IsDefault = string.IsNullOrWhiteSpace(resolveName),
                 IsShared = false,
-                ResolveKey = resolveName?.Trim(),
+                ResolveKey = resolveName?.Trim()!,
                 ConstructorParameters = constructorParameters
             };
             Register(contractType, resolveType);
@@ -597,7 +597,7 @@ namespace ZeroLevel.DependencyInjection
                 ImplementationType = implementationType,
                 IsDefault = string.IsNullOrWhiteSpace(resolveName),
                 IsShared = shared,
-                ResolveKey = resolveName?.Trim(),
+                ResolveKey = resolveName?.Trim()!,
                 ConstructorParameters = constructorParameters
             };
             Register(contractType, resolveType);
@@ -614,6 +614,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="implementation">Instance</param>
         public void Register<TContract>(TContract implementation)
         {
+            if(implementation == null) throw new ArgumentNullException(nameof(implementation));
             var resolveType = new ResolveTypeInfo
             {
                 ImplementationType = implementation.GetType(),
@@ -627,6 +628,7 @@ namespace ZeroLevel.DependencyInjection
 
         public void Register(Type contractType, object implementation)
         {
+            if (implementation == null) throw new ArgumentNullException(nameof(implementation));
             var resolveType = new ResolveTypeInfo
             {
                 ImplementationType = implementation.GetType(),
@@ -640,6 +642,7 @@ namespace ZeroLevel.DependencyInjection
 
         public void Register<TContract>(TContract implementation, string resolveName)
         {
+            if (implementation == null) throw new ArgumentNullException(nameof(implementation));
             var resolveType = new ResolveTypeInfo
             {
                 ImplementationType = implementation.GetType(),
@@ -653,6 +656,7 @@ namespace ZeroLevel.DependencyInjection
 
         public void Register(Type contractType, string resolveName, object implementation)
         {
+            if (implementation == null) throw new ArgumentNullException(nameof(implementation));
             var resolveType = new ResolveTypeInfo
             {
                 ImplementationType = implementation.GetType(),
@@ -952,7 +956,7 @@ namespace ZeroLevel.DependencyInjection
 
         public bool IsResolvingExists(Type type, string resolveName)
         {
-            return GetResolvedType(type, resolveName)?.Item1 != null;
+            return GetResolvedType(type, resolveName)?.Item1 != null!;
         }
 
         private Tuple<ResolveTypeInfo, bool> GetResolvedType(Type type, string resolveName)
@@ -1110,12 +1114,12 @@ namespace ZeroLevel.DependencyInjection
         /// </summary>
         private void FillParametrizedFieldsAndProperties(object instance)
         {
-            if (instance != null)
+            if (instance != null!)
             {
                 foreach (var property in instance.GetType().GetProperties(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy))
                 {
                     var attr = property.GetCustomAttribute<ParameterAttribute>();
-                    if (attr != null)
+                    if (attr != null!)
                     {
                         var parameterType = attr.Type ?? property.PropertyType;
                         var parameterName = attr.Name ?? property.Name;
@@ -1125,7 +1129,7 @@ namespace ZeroLevel.DependencyInjection
                 foreach (var field in instance.GetType().GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy))
                 {
                     var attr = field.GetCustomAttribute<ParameterAttribute>();
-                    if (attr != null)
+                    if (attr != null!)
                     {
                         var parameterType = attr.Type ?? field.FieldType;
                         var parameterName = string.IsNullOrWhiteSpace(attr.Name) ? field.Name : attr.Name;
@@ -1137,7 +1141,7 @@ namespace ZeroLevel.DependencyInjection
 
         private void ComposeParts(object instance)
         {
-            if (instance != null)
+            if (instance != null!)
             {
                 var resolve_properties = CollectResolvingProperties(instance.GetType());
                 var resolve_fields = CollectResolvingFields(instance.GetType());
@@ -1153,13 +1157,13 @@ namespace ZeroLevel.DependencyInjection
                         f.GetCustomAttribute<ResolveAttribute>());
                     f.SetValue(instance, resolve_instance);
                 }
+                FillParametrizedFieldsAndProperties(instance);
             }
-            FillParametrizedFieldsAndProperties(instance);
         }
 
         private void RecursiveCompose(object instance, HashSet<object> set)
         {
-            if (instance != null)
+            if (instance != null!)
             {
                 foreach (var f in
                 instance.GetType().GetFields(BindingFlags.Public |
@@ -1178,8 +1182,8 @@ namespace ZeroLevel.DependencyInjection
                         }
                     }
                 }
+                ComposeParts(instance);
             }
-            ComposeParts(instance);
         }
 
         public void Compose(object instance, bool recursive = true)
@@ -1229,7 +1233,7 @@ namespace ZeroLevel.DependencyInjection
                         {
                             Log.SystemError(ex, $"[Container] Singletone dispose error. Instance: '{item?.GetType()?.FullName ?? string.Empty}'");
                         }
-                        if (item!.GenericInstanceCachee != null)
+                        if (item!.GenericInstanceCachee != null!)
                         {
                             foreach (var gitem in item.GenericInstanceCachee.Values)
                             {
@@ -1307,7 +1311,7 @@ namespace ZeroLevel.DependencyInjection
         {
             if (_everything.Value.ContainsKey<T>(key))
                 return _everything.Value.Get<T>(key);
-            return default(T);
+            return default(T)!;
         }
 
         public T GetOrDefault<T>(string key, T defaultValue)

ZeroLevel/Services/DependencyInjection/ContainerFactory.cs

@@ -89,7 +89,7 @@ namespace ZeroLevel.DependencyInjection
             {
                 return exists;
             }
-            return null;
+            return null!;
         }
 
         public bool Remove(string containerName)

ZeroLevel/Services/DependencyInjection/Contracts/IContainerRegister.cs

@@ -161,7 +161,7 @@ namespace ZeroLevel.DependencyInjection
         /// <typeparam name="TImplementation">Dependency resolution</typeparam>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryRegister<TContract, TImplementation>(Action<Exception> fallback = null);
+        bool TryRegister<TContract, TImplementation>(Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration
@@ -171,7 +171,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="resolveName">Dependency name</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryRegister<TContract, TImplementation>(string resolveName, Action<Exception> fallback = null);
+        bool TryRegister<TContract, TImplementation>(string resolveName, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration
@@ -181,7 +181,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="shared">true - for singletone</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryRegister<TContract, TImplementation>(bool shared, Action<Exception> fallback = null);
+        bool TryRegister<TContract, TImplementation>(bool shared, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration
@@ -192,7 +192,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="shared">true - for singletone</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryRegister<TContract, TImplementation>(string resolveName, bool shared, Action<Exception> fallback = null);
+        bool TryRegister<TContract, TImplementation>(string resolveName, bool shared, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration
@@ -201,7 +201,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="implementationType">Dependency resolution</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryRegister(Type contractType, Type implementationType, Action<Exception> fallback = null);
+        bool TryRegister(Type contractType, Type implementationType, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration
@@ -211,7 +211,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="resolveName">Dependency name</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryRegister(Type contractType, Type implementationType, string resolveName, Action<Exception> fallback = null);
+        bool TryRegister(Type contractType, Type implementationType, string resolveName, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration
@@ -221,7 +221,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="shared">true - for singletone</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryRegister(Type contractType, Type implementationType, bool shared, Action<Exception> fallback = null);
+        bool TryRegister(Type contractType, Type implementationType, bool shared, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration
@@ -232,7 +232,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="shared">true - for singletone</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryRegister(Type contractType, Type implementationType, string resolveName, bool shared, Action<Exception> fallback = null);
+        bool TryRegister(Type contractType, Type implementationType, string resolveName, bool shared, Action<Exception> fallback = null!);
 
         #endregion Safe register
 
@@ -246,7 +246,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="constructorParameters">Ctor args</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryParameterizedRegister<TContract, TImplementation>(object[] constructorParameters, Action<Exception> fallback = null);
+        bool TryParameterizedRegister<TContract, TImplementation>(object[] constructorParameters, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration with constructor parameters
@@ -257,7 +257,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="constructorParameters">Ctor args</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryParameterizedRegister<TContract, TImplementation>(string resolveName, object[] constructorParameters, Action<Exception> fallback = null);
+        bool TryParameterizedRegister<TContract, TImplementation>(string resolveName, object[] constructorParameters, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration with constructor parameters
@@ -268,7 +268,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="constructorParameters">Ctor args</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryParameterizedRegister<TContract, TImplementation>(bool shared, object[] constructorParameters, Action<Exception> fallback = null);
+        bool TryParameterizedRegister<TContract, TImplementation>(bool shared, object[] constructorParameters, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration with constructor parameters
@@ -280,7 +280,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="constructorParameters">Ctor args</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryParameterizedRegister<TContract, TImplementation>(string resolveName, bool shared, object[] constructorParameters, Action<Exception> fallback = null);
+        bool TryParameterizedRegister<TContract, TImplementation>(string resolveName, bool shared, object[] constructorParameters, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration with constructor parameters
@@ -290,7 +290,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="constructorParameters">Ctor args</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryParameterizedRegister(Type contractType, Type implementationType, object[] constructorParameters, Action<Exception> fallback = null);
+        bool TryParameterizedRegister(Type contractType, Type implementationType, object[] constructorParameters, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration with constructor parameters
@@ -301,7 +301,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="constructorParameters">Ctor args</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryParameterizedRegister(Type contractType, Type implementationType, string resolveName, object[] constructorParameters, Action<Exception> fallback = null);
+        bool TryParameterizedRegister(Type contractType, Type implementationType, string resolveName, object[] constructorParameters, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration with constructor parameters
@@ -312,7 +312,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="constructorParameters">Ctor args</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryParameterizedRegister(Type contractType, Type implementationType, bool shared, object[] constructorParameters, Action<Exception> fallback = null);
+        bool TryParameterizedRegister(Type contractType, Type implementationType, bool shared, object[] constructorParameters, Action<Exception> fallback = null!);
 
         /// <summary>
         /// Safe dependency resolution registration with constructor parameters
@@ -324,7 +324,7 @@ namespace ZeroLevel.DependencyInjection
         /// <param name="constructorParameters">Ctor args</param>
         /// <param name="fallback">Error handler</param>
         /// <returns>true - registration successfully completed</returns>
-        bool TryParameterizedRegister(Type contractType, Type implementationType, string resolveName, bool shared, object[] constructorParameters, Action<Exception> fallback = null);
+        bool TryParameterizedRegister(Type contractType, Type implementationType, string resolveName, bool shared, object[] constructorParameters, Action<Exception> fallback = null!);
 
         #endregion Safe register with parameters
     }

ZeroLevel/Services/DependencyInjection/Internal/ConstructorMetadata.cs

@@ -25,17 +25,17 @@ namespace ZeroLevel.DependencyInjection
                     var parameterAttribute = p.GetCustomAttribute<ParameterAttribute>();
                     var resolveAttribute = p.GetCustomAttribute<ResolveAttribute>();
 
-                    var kind = (parameterAttribute != null) ? ConstructorParameterKind.Parameter :
+                    var kind = (parameterAttribute != null!) ? ConstructorParameterKind.Parameter :
-                    (resolveAttribute != null) ? ConstructorParameterKind.Dependency : ConstructorParameterKind.None;
+                    (resolveAttribute != null!) ? ConstructorParameterKind.Dependency : ConstructorParameterKind.None;
 
                     return new ConstructorParameter
                     {
                         Type = p.ParameterType,
                         ParameterKind = kind,
-                        ParameterResolveName = (kind == ConstructorParameterKind.Parameter) ? parameterAttribute?.Name ?? p.Name :
+                        ParameterResolveName = ((kind == ConstructorParameterKind.Parameter) ? parameterAttribute?.Name ?? p.Name :
-                            (kind == ConstructorParameterKind.Dependency) ? resolveAttribute?.ResolveName : null,
+                            (kind == ConstructorParameterKind.Dependency) ? resolveAttribute?.ResolveName : null)!,
                         ParameterResolveType = (kind == ConstructorParameterKind.Parameter) ? parameterAttribute?.Type ?? p.ParameterType :
-                            (kind == ConstructorParameterKind.Dependency) ? resolveAttribute?.ContractType ?? p.ParameterType : null,
+                            (kind == ConstructorParameterKind.Dependency) ? resolveAttribute?.ContractType ?? p.ParameterType : null!,
                         IsNullable = IsNullable(p.ParameterType)
                     };
                 }).ToList();
@@ -44,7 +44,7 @@ namespace ZeroLevel.DependencyInjection
         private static bool IsNullable(Type type)
         {
             if (!type.IsValueType) return true; // ref-type
-            if (Nullable.GetUnderlyingType(type) != null) return true; // Nullable<T>
+            if (Nullable.GetUnderlyingType(type) != null!) return true; // Nullable<T>
             return false; // value-type
         }
 
@@ -56,7 +56,7 @@ namespace ZeroLevel.DependencyInjection
         /// <returns>true - if the constructor can be called with the arguments passed</returns>
         public bool IsMatch(object[] args, out object[] parameters)
         {
-            parameters = null;
+            parameters = null!;
             int arg_index = 0;
             if (Parameters.Count > 0)
             {

ZeroLevel/Services/DependencyInjection/ParameterAttribute.cs

@@ -9,7 +9,7 @@ namespace ZeroLevel.DependencyInjection
 
         public ParameterAttribute()
         {
-            this.Type = null;
+            this.Type = null!;
             this.Name = string.Empty;
         }
 
@@ -21,7 +21,7 @@ namespace ZeroLevel.DependencyInjection
 
         public ParameterAttribute(string parameterName)
         {
-            this.Type = null;
+            this.Type = null!;
             this.Name = parameterName;
         }
 

ZeroLevel/Services/DependencyInjection/ResolveAttribute.cs

@@ -9,12 +9,12 @@ namespace ZeroLevel.DependencyInjection
 
         public ResolveAttribute()
         {
-            ResolveName = string.Empty; ContractType = null;
+            ResolveName = string.Empty; ContractType = null!;
         }
 
         public ResolveAttribute(string resolveName)
         {
-            ResolveName = resolveName; ContractType = null;
+            ResolveName = resolveName; ContractType = null!;
         }
 
         public ResolveAttribute(Type contractType)

ZeroLevel/Services/Encryption/AesEncryptor.cs

@@ -17,7 +17,7 @@ namespace ZeroLevel.Services.Encryption
 
         #endregion Crypt fields
 
-        public AesEncryptor(Stream stream, string password, byte[] salt = null)
+        public AesEncryptor(Stream stream, string password, byte[] salt = null!)
         {
             _aes = Aes.Create();
             using (var pdb = new Rfc2898DeriveBytes(password, SALT))
@@ -54,7 +54,7 @@ namespace ZeroLevel.Services.Encryption
             output.Flush();
         }
 
-        public static byte[] Encrypt(byte[] plain, string password, byte[] salt = null)
+        public static byte[] Encrypt(byte[] plain, string password, byte[] salt = null!)
         {
             using (var aes = Aes.Create())
             {
@@ -75,7 +75,7 @@ namespace ZeroLevel.Services.Encryption
             }
         }
 
-        public static byte[] Encrypt(Stream stream, string password, byte[] salt = null)
+        public static byte[] Encrypt(Stream stream, string password, byte[] salt = null!)
         {
             using (var aes = Aes.Create())
             {
@@ -96,7 +96,7 @@ namespace ZeroLevel.Services.Encryption
             }
         }
 
-        public static void Encrypt(Stream inputStream, Stream outputStream, string password, byte[] salt = null)
+        public static void Encrypt(Stream inputStream, Stream outputStream, string password, byte[] salt = null!)
         {
             using (var aes = Aes.Create())
             {
@@ -113,7 +113,7 @@ namespace ZeroLevel.Services.Encryption
             }
         }
 
-        public static byte[] Decrypt(byte[] cipher, string password, byte[] salt = null)
+        public static byte[] Decrypt(byte[] cipher, string password, byte[] salt = null!)
         {
             using (var aes = Aes.Create())
             {
@@ -134,7 +134,7 @@ namespace ZeroLevel.Services.Encryption
             }
         }
 
-        public static byte[] Decrypt(Stream stream, string password, byte[] salt = null)
+        public static byte[] Decrypt(Stream stream, string password, byte[] salt = null!)
         {
             using (var aes = Aes.Create())
             {
@@ -155,7 +155,7 @@ namespace ZeroLevel.Services.Encryption
             }
         }
 
-        public static void Decrypt(Stream inputStream, Stream outputStream, string password, byte[] salt = null)
+        public static void Decrypt(Stream inputStream, Stream outputStream, string password, byte[] salt = null!)
         {
             using (var aes = Aes.Create())
             {

ZeroLevel/Services/Extensions/ArrayExtensions.cs

@@ -50,12 +50,12 @@ namespace ZeroLevel
 
             for (int a = 0; a < array.Length; a++)
             {
-                if (array[a].Equals(candidate[0]))
+                if (array[a]!.Equals(candidate[0]))
                 {
                     int i = 1;
                     for (; i < candidate.Length && (a + i) < array.Length; i++)
                     {
-                        if (false == array[a + i].Equals(candidate[i]))
+                        if (false == array[a + i]!.Equals(candidate[i]))
                             break;
                     }
                     if (i == candidate.Length)

ZeroLevel/Services/Extensions/BitArrayExtensions.cs

@@ -12,7 +12,7 @@ namespace ZeroLevel.Extensions
         // <returns>The bit array converted to an array of bytes.</returns>
         internal static byte[] ToBytes(this FastBitArray bits)
         {
-            if (bits == null) return null;
+            if (bits == null!) return null!;
             var numBytes = bits.Count / 8;
             if (bits.Count % 8 != 0) numBytes++;
             var bytes = new byte[numBytes];

ZeroLevel/Services/Extensions/CollectionComparsionExtensions.cs

@@ -27,7 +27,7 @@ namespace ZeroLevel
 
             public int GetHashCode(T obj)
             {
-                return obj.GetHashCode();
+                return obj?.GetHashCode() ?? 0;
             }
         }
 
@@ -36,8 +36,8 @@ namespace ZeroLevel
         /// </summary>
         public static bool StringEnumerableEquals(this IEnumerable<string> A, IEnumerable<string> B)
         {
-            if (A == null && B == null) return true;
+            if (A == null && B == null!) return true;
-            if (A == null || B == null) return false;
+            if (A == null || B == null!) return false;
             return A.Count() == B.Count() && A.Intersect(B).Count() == B.Count();
         }
 
@@ -46,15 +46,15 @@ namespace ZeroLevel
         /// </summary>
         public static bool NoOrderingEquals<T>(this IEnumerable<T> A, IEnumerable<T> B)
         {
-            if (A == null && B == null) return true;
+            if (A == null && B == null!) return true;
-            if (A == null || B == null) return false;
+            if (A == null || B == null!) return false;
             return A.Count() == B.Count() && A.Intersect(B, new SimpleComparer<T>()).Count() == B.Count();
         }
 
         public static bool NoOrderingEquals<T>(this IEnumerable<T> A, IEnumerable<T> B, Func<T, T, bool> comparer)
         {
-            if (A == null && B == null) return true;
+            if (A == null && B == null!) return true;
-            if (A == null || B == null) return false;
+            if (A == null || B == null!) return false;
             return A.Count() == B.Count() && A.Intersect(B, new SimpleComparer<T>(comparer)).Count() == B.Count();
         }
 
@@ -63,15 +63,15 @@ namespace ZeroLevel
         /// </summary>
         public static bool OrderingEquals<T>(this IEnumerable<T> A, IEnumerable<T> B)
         {
-            if (A == null && B == null) return true;
+            if (A == null && B == null!) return true;
-            if (A == null || B == null) return false;
+            if (A == null || B == null!) return false;
             if (A.Count() != B.Count()) return false;
             var enumA = A.GetEnumerator();
             var enumB = B.GetEnumerator();
             while (enumA.MoveNext() && enumB.MoveNext())
             {
-                if (enumA.Current == null && enumB.Current == null) continue;
+                if (enumA.Current == null && enumB.Current == null!) continue;
-                if (enumA.Current == null || enumB.Current == null) return false;
+                if (enumA.Current == null || enumB.Current == null!) return false;
                 if (enumA.Current.Equals(enumB.Current) == false) return false;
             }
             return true;
@@ -79,15 +79,15 @@ namespace ZeroLevel
 
         public static bool OrderingEquals<T>(this IEnumerable<T> A, IEnumerable<T> B, Func<T, T, bool> comparer)
         {
-            if (A == null && B == null) return true;
+            if (A == null && B == null!) return true;
-            if (A == null || B == null) return false;
+            if (A == null || B == null!) return false;
             if (A.Count() != B.Count()) return false;
             var enumA = A.GetEnumerator();
             var enumB = B.GetEnumerator();
             while (enumA.MoveNext() && enumB.MoveNext())
             {
-                if (enumA.Current == null && enumB.Current == null) continue;
+                if (enumA.Current == null && enumB.Current == null!) continue;
-                if (enumA.Current == null || enumB.Current == null) return false;
+                if (enumA.Current == null || enumB.Current == null!) return false;
                 if (comparer(enumA.Current, enumB.Current) == false) return false;
             }
             return true;
@@ -99,10 +99,10 @@ namespace ZeroLevel
         public static int GetEnumHashCode<T>(this IEnumerable<T> A)
         {
             int hc = 0;
-            if (A != null)
+            if (A != null!)
             {
                 foreach (var p in A)
-                    hc ^= p.GetHashCode();
+                    hc ^= p?.GetHashCode() ?? 0;
             }
             return hc;
         }

ZeroLevel/Services/Extensions/EncodingEx.cs

@@ -25,7 +25,7 @@ namespace ZeroLevel.Services.Extensions
 
         public EncodingEx(Encoding baseEncoding) : base(baseEncoding.CodePage)
         {
-            if (baseEncoding == null) throw new ArgumentNullException("baseEncoding");
+            if (baseEncoding == null!) throw new ArgumentNullException("baseEncoding");
             _baseEncoding = baseEncoding;
         }
 

ZeroLevel/Services/Extensions/EndpointExtensions.cs

@@ -7,23 +7,23 @@ namespace ZeroLevel.Extensions
         public const string HTTP_SCHEMA = "http";
         public const string HTTPS_SCHEMA = "https";
 
-        public static string ToHttpUrl(this EndPoint endPoint, string schema, string rawUrl = null)
+        public static string ToHttpUrl(this EndPoint endPoint, string schema, string rawUrl = null!)
         {
             if (endPoint is IPEndPoint)
             {
                 var ipEndPoint = endPoint as IPEndPoint;
-                return CreateHttpUrl(schema, ipEndPoint.Address.ToString(), ipEndPoint.Port,
+                return CreateHttpUrl(schema, ipEndPoint?.Address?.ToString() ?? string.Empty, ipEndPoint?.Port ?? 0,
                     rawUrl != null ? rawUrl.TrimStart('/') : string.Empty);
             }
 
             if (endPoint is DnsEndPoint)
             {
                 var dnsEndpoint = endPoint as DnsEndPoint;
-                return CreateHttpUrl(schema, dnsEndpoint.Host, dnsEndpoint.Port,
+                return CreateHttpUrl(schema, dnsEndpoint?.Host ?? string.Empty, dnsEndpoint?.Port ?? 0,
                     rawUrl != null ? rawUrl.TrimStart('/') : string.Empty);
             }
 
-            return null;
+            return null!;
         }
 
         public static string ToHttpUrl(this EndPoint endPoint, string schema, string formatString,
@@ -32,18 +32,18 @@ namespace ZeroLevel.Extensions
             if (endPoint is IPEndPoint)
             {
                 var ipEndPoint = endPoint as IPEndPoint;
-                return CreateHttpUrl(schema, ipEndPoint.Address.ToString(), ipEndPoint.Port,
+                return CreateHttpUrl(schema, ipEndPoint?.Address?.ToString() ?? string.Empty, ipEndPoint?.Port ?? 0,
                     string.Format(formatString.TrimStart('/'), args));
             }
 
             if (endPoint is DnsEndPoint)
             {
                 var dnsEndpoint = endPoint as DnsEndPoint;
-                return CreateHttpUrl(schema, dnsEndpoint.Host, dnsEndpoint.Port,
+                return CreateHttpUrl(schema, dnsEndpoint?.Host ?? string.Empty, dnsEndpoint?.Port ?? 0,
                     string.Format(formatString.TrimStart('/'), args));
             }
 
-            return null;
+            return null!;
         }
 
         private static string CreateHttpUrl(string schema, string host, int port, string path)

ZeroLevel/Services/Extensions/EnumExtensions.cs

@@ -18,13 +18,13 @@ namespace ZeroLevel
             var type = enumVal.GetType();
             var memInfo = type.GetMember(enumVal.ToString());
             var attributes = memInfo[0].GetCustomAttributes(typeof(T), false);
-            return (attributes.Length > 0) ? (T)attributes[0] : null;
+            return ((attributes.Length > 0) ? (T)attributes[0] : null)!;
         }
 
         public static string Description(this Enum enumVal)
         {
             var attr = enumVal.GetAttributeOfType<DescriptionAttribute>();
-            return attr?.Description;
+            return attr?.Description!;
         }
 
         public static T GetValueFromDescription<T>(string description)
@@ -35,7 +35,7 @@ namespace ZeroLevel
             {
                 var attribute = Attribute.GetCustomAttribute(field,
                     typeof(DescriptionAttribute)) as DescriptionAttribute;
-                if (attribute != null)
+                if (attribute != null!)
                 {
                     if (attribute.Description == description)
                         return (T)field.GetValue(null);
@@ -47,7 +47,7 @@ namespace ZeroLevel
                 }
             }
             throw new ArgumentException("Not found.", nameof(description));
-            // or return default(T);
+            // or return default(T)!;
         }
     }
 }

ZeroLevel/Services/Extensions/EnumerableExtensions.cs

@@ -19,10 +19,10 @@ namespace ZeroLevel
 
         public static bool IsEmpty<T>(this IEnumerable<T> collection)
         {
-            if (collection == null)
+            if (collection == null!)
                 return true;
             var coll = collection as ICollection;
-            if (coll != null)
+            if (coll != null!)
                 return coll.Count == 0;
             return !collection.Any();
         }

ZeroLevel/Services/Extensions/FPCommon.cs

@@ -82,12 +82,12 @@ namespace ZeroLevel.Services.Extensions
         /// </exception>
         public T Match<T>(Func<TL, T> ofLeft, Func<TR, T> ofRight)
         {
-            if (ofLeft == null)
+            if (ofLeft == null!)
             {
                 throw new ArgumentNullException(nameof(ofLeft));
             }
 
-            if (ofRight == null)
+            if (ofRight == null!)
             {
                 throw new ArgumentNullException(nameof(ofRight));
             }
@@ -104,12 +104,12 @@ namespace ZeroLevel.Services.Extensions
         /// </exception>
         public void Match(Action<TL> ofLeft, Action<TR> ofRight)
         {
-            if (ofLeft == null)
+            if (ofLeft == null!)
             {
                 throw new ArgumentNullException(nameof(ofLeft));
             }
 
-            if (ofRight == null)
+            if (ofRight == null!)
             {
                 throw new ArgumentNullException(nameof(ofRight));
             }
@@ -124,9 +124,9 @@ namespace ZeroLevel.Services.Extensions
             }
         }
 
-        public TL LeftOrDefault() => Match(l => l, r => default(TL));
+        public TL LeftOrDefault() => Match(l => l, r => default(TL))!;
 
-        public TR RightOrDefault() => Match(l => default(TR), r => r);
+        public TR RightOrDefault() => Match(l => default(TR), r => r)!;
 
         public Either<TR, TL> Swap() => Match(Right<TR, TL>, Left<TR, TL>);
 

ZeroLevel/Services/Extensions/LinqExtension.cs

@@ -4,7 +4,7 @@ namespace System.Linq
 {
     public static class LinqExtension
     {
-        public static void ThrowIfNull<T>(this T val, string message = null)
+        public static void ThrowIfNull<T>(this T val, string message = null!)
         {
             if (null == val)
                 throw new ArgumentNullException(message);
@@ -35,11 +35,11 @@ namespace System.Linq
                 }
                 else if (hasLeft)
                 {
-                    yield return new T[] { leftEnumerator.Current, default(T) };
+                    yield return new T[] { leftEnumerator.Current, default(T)! };
                 }
                 else if (hasRight)
                 {
-                    yield return new T[] { default(T), rightEnumerator.Current };
+                    yield return new T[] { default(T)!, rightEnumerator.Current };
                 }
 
                 hasLeft = leftEnumerator.MoveNext();
@@ -50,7 +50,7 @@ namespace System.Linq
         public static IEnumerable<TSource> DistinctBy<TSource, TKey>
              (this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
         {
-            if (source != null)
+            if (source != null!)
             {
                 var seenKeys = new HashSet<TKey>();
                 foreach (TSource element in source)
@@ -78,7 +78,7 @@ namespace System.Linq
         }
         public static IEnumerable<IEnumerable<T>> Chunkify<T>(this IEnumerable<T> source, int size)
         {
-            if (source == null)
+            if (source == null!)
             {
                 yield break;
             }

ZeroLevel/Services/Extensions/Monades.cs

@@ -9,7 +9,7 @@ namespace ZeroLevel
         public static TResult With<TInput, TResult>(this TInput o, Func<TInput, TResult> evaluator)
         {
             if (null != o) return evaluator(o);
-            return default(TResult);
+            return default(TResult)!;
         }
 
         #endregion With
@@ -25,7 +25,7 @@ namespace ZeroLevel
         public static TResult Return<TInput, TResult>(this TInput o, Func<TInput, TResult> evaluator)
         {
             if (null != o) return evaluator(o);
-            return default(TResult);
+            return default(TResult)!;
         }
 
         #endregion Return
@@ -44,8 +44,8 @@ namespace ZeroLevel
 
         public static TInput If<TInput>(this TInput o, Predicate<TInput> evaluator)
         {
-            if (null != o) return evaluator(o) ? o : default(TInput);
+            if (null != o) return evaluator(o) ? o : default(TInput)!;
-            return default(TInput);
+            return default(TInput)!;
         }
 
         public static TOutput Either<TInput, TOutput>(this TInput o, Func<TInput, bool> condition,
@@ -54,7 +54,7 @@ namespace ZeroLevel
 
         public static TOutput Either<TInput, TOutput>(this TInput o, Func<TInput, TOutput> ifTrue,
             Func<TInput, TOutput> ifFalse)
-            => o.Either(x => x != null, ifTrue, ifFalse);
+            => o.Either(x => x != null!, ifTrue, ifFalse);
 
         #endregion If
 

ZeroLevel/Services/Extensions/TaskExtension.cs

@@ -7,28 +7,28 @@ namespace ZeroLevel.Services.Extensions
     {
         public static T WaitResult<T>(this Task<T> task)
         {
-            if (task == null)
+            if (task == null!)
             {
                 throw new ArgumentNullException(nameof(task));
             }
             task.Wait();
             if (task.IsFaulted)
             {
-                if (task.Exception != null) throw task.Exception;
+                if (task.Exception != null!) throw task.Exception;
             }
             return task.Result;
         }
 
         public static void WaitWithoutResult(this Task task)
         {
-            if (task == null)
+            if (task == null!)
             {
                 throw new ArgumentNullException(nameof(task));
             }
             task.Wait();
             if (task.IsFaulted)
             {
-                if (task.Exception != null) throw task.Exception;
+                if (task.Exception != null!) throw task.Exception;
             }
         }
     }

ZeroLevel/Services/Extensions/TypeExtensions.cs

@@ -20,7 +20,7 @@ namespace ZeroLevel
             // The value returned contains the StateMachineType property.
             // Null is returned if the attribute isn't present for the method.
             var attrib = (AsyncStateMachineAttribute)method.GetCustomAttribute(attType);
-            return (attrib != null);
+            return (attrib != null!);
         }
 
         public static object GetDefault(this Type type)
@@ -29,12 +29,12 @@ namespace ZeroLevel
             {
                 return Activator.CreateInstance(type);
             }
-            return null;
+            return null!;
         }
 
         public static object GetPropValue(this object src, string propName)
         {
-            return src?.GetType()?.GetProperty(propName)?.GetValue(src, null);
+            return (src?.GetType()?.GetProperty(propName)?.GetValue(src, null))!;
         }
 
         public static bool IsAssignableToGenericType(this Type givenType, Type genericType)
@@ -51,7 +51,7 @@ namespace ZeroLevel
                 return true;
 
             Type baseType = givenType.BaseType;
-            if (baseType == null) return false;
+            if (baseType == null!) return false;
 
             return IsAssignableToGenericType(baseType, genericType);
         }

ZeroLevel/Services/Fiber.cs

@@ -12,8 +12,8 @@ namespace ZeroLevel.Services
             public Step _next;
         }
 
-        Step _head = null;
+        Step _head = null!;
-        Step _tail = null;
+        Step _tail = null!;
 
         public Fiber()
         {
@@ -21,13 +21,13 @@ namespace ZeroLevel.Services
 
         public Fiber Add(Func<IEverythingStorage, IEverythingStorage> action)
         {
-            if (_head == null)
+            if (_head == null!)
             {
-                _head = _tail = new Step { _handler = action, _next = null };
+                _head = _tail = new Step { _handler = action, _next = null! };
             }
             else
             {
-                var s = new Step { _handler = action, _next = null };
+                var s = new Step { _handler = action, _next = null! };
                 _tail._next = s;
                 _tail = s;
             }
@@ -36,16 +36,16 @@ namespace ZeroLevel.Services
 
         public IEnumerable<Func<IEverythingStorage, IEverythingStorage>> Iterate()
         {
-            if (_head == null) yield break;
+            if (_head == null!) yield break;
             var current = _head;
-            while (current != null)
+            while (current != null!)
             {
                 yield return current._handler;
                 current = current._next;
             }
         }
 
-        public IEverythingStorage Run(IEverythingStorage buffer = null)
+        public IEverythingStorage Run(IEverythingStorage buffer = null!)
         {
             var storage = buffer;
             foreach (var a in Iterate())

ZeroLevel/Services/FileSystem/BigFileParser.cs

@@ -16,7 +16,7 @@ namespace ZeroLevel.Services.FileSystem
             {
                 throw new ArgumentNullException(nameof(filePath));
             }
-            if (parser == null)
+            if (parser == null!)
             {
                 throw new ArgumentNullException(nameof(parser));
             }
@@ -42,10 +42,10 @@ namespace ZeroLevel.Services.FileSystem
                     {
                         string line;
                         buffer = new T[batchSize];
-                        while ((line = sr.ReadLine()) != null)
+                        while ((line = sr.ReadLine()) != null!)
                         {
                             var value = _parser.Invoke(line);
-                            if (skipNull && value == null) continue;
+                            if (skipNull && value == null!) continue;
                             buffer[buffer_index] = value;
                             buffer_index++;
                             if (buffer_index >= batchSize)
@@ -77,7 +77,7 @@ namespace ZeroLevel.Services.FileSystem
                     using (StreamReader sr = new StreamReader(bs))
                     {
                         string line;
-                        while ((line = sr.ReadLine()) != null)
+                        while ((line = sr.ReadLine()) != null!)
                         {
                             yield return _parser.Invoke(line);
                         }

ZeroLevel/Services/FileSystem/FSUtils.cs

@@ -42,7 +42,7 @@ namespace ZeroLevel.Services.FileSystem
             return folderName;
         }
 
-        public static string GetAppLocalDbDirectory(string dbFolderName = null)
+        public static string GetAppLocalDbDirectory(string dbFolderName = null!)
         {
             dbFolderName = Path.Combine(Configuration.BaseDirectory, dbFolderName ?? "db");
             if (false == Directory.Exists(dbFolderName))
@@ -153,7 +153,7 @@ namespace ZeroLevel.Services.FileSystem
         /// </summary>
         public static string PathCorrection(string path)
         {
-            if (path == null) return string.Empty;
+            if (path == null!) return string.Empty;
             var result = new char[path.Length];
             var index = 0;
             foreach (char c in path)
@@ -173,7 +173,7 @@ namespace ZeroLevel.Services.FileSystem
         /// </summary>
         public static string FileNameCorrection(string name, bool isRootPath = false)
         {
-            if (name == null) return string.Empty;
+            if (name == null!) return string.Empty;
             // The reserved filenames
             if (StartWithInvalidWindowsPrefix(name))
             {
@@ -207,7 +207,7 @@ namespace ZeroLevel.Services.FileSystem
         /// </summary>
         public static string FileNameCorrection(string name, char replacedSymbol, bool isRootPath = false)
         {
-            if (name == null) return string.Empty;
+            if (name == null!) return string.Empty;
             if (_invalid_filename_characters.IndexOf(replacedSymbol) >= 0)
             {
                 throw new ArgumentException($"The sybmol '{replacedSymbol}' is invalid for windows filenames");
@@ -250,7 +250,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <returns></returns>
         public static string FileNameCorrection(string path, char replaceChar)
         {
-            if (path == null) return string.Empty;
+            if (path == null!) return string.Empty;
             var result = new char[path.Length];
             var index = 0;
             foreach (char c in path)
@@ -286,7 +286,7 @@ namespace ZeroLevel.Services.FileSystem
             }
             finally
             {
-                if (fileStream != null)
+                if (fileStream != null!)
                 {
                     fileStream.Close();
                     fileStream.Dispose();
@@ -309,7 +309,7 @@ namespace ZeroLevel.Services.FileSystem
             }
             finally
             {
-                if (fileStream != null)
+                if (fileStream != null!)
                 {
                     fileStream.Close();
                     fileStream.Dispose();
@@ -319,14 +319,14 @@ namespace ZeroLevel.Services.FileSystem
             return false;
         }
 
-        public static void PackFolder(string sourceFolder, string zipPath, Func<FileInfo, bool> selector = null)
+        public static void PackFolder(string sourceFolder, string zipPath, Func<FileInfo, bool> selector = null!)
         {
             var tmp = FSUtils.GetAppLocalTemporaryDirectory();
             var tmpDir = Directory.CreateDirectory(tmp);
             var files = new DirectoryInfo(sourceFolder)
                 .GetFiles("*.*", SearchOption.AllDirectories)
                 .AsEnumerable();
-            if (selector != null)
+            if (selector != null!)
             {
                 files = files.Where(selector);
             }

ZeroLevel/Services/FileSystem/FileArchive.cs

@@ -237,7 +237,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="text">Text</param>
         /// <param name="subfolder_name">Archive file name (HH_mm_ss_fff_counter.{ext} by default)</param>
         /// <returns></returns>
-        public void StoreText(string text, string subfolder_name = null, string file_name = null)
+        public void StoreText(string text, string subfolder_name = null!, string file_name = null!)
         {
             Apply(new StoreText(text, CreateArchiveFilePath(subfolder_name, file_name)));
         }
@@ -248,12 +248,12 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="file_path">File path</param>
         /// <param name="subfolder_name">Archive file name (original file name by default)</param>
         /// <returns></returns>
-        public void Store(string file_path, string subfolder_name = null, string file_name = null)
+        public void Store(string file_path, string subfolder_name = null!, string file_name = null!)
         {
             Apply(new StoreFile(file_path, CreateArchiveFilePath(subfolder_name, file_name)));
         }
 
-        public void Store(string file_path, bool immediate, string subfolder_name = null, string file_name = null)
+        public void Store(string file_path, bool immediate, string subfolder_name = null!, string file_name = null!)
         {
             if (immediate)
             {
@@ -271,7 +271,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="stream">Data stream for reading</param>
         /// <param name="subfolder_name">Archive file name (HH_mm_ss_fff_counter.{ext} by default)</param>
         /// <returns></returns>
-        public void Store(Stream stream, string subfolder_name = null, string file_name = null)
+        public void Store(Stream stream, string subfolder_name = null!, string file_name = null!)
         {
             Apply(new StoreStream(stream, CreateArchiveFilePath(subfolder_name, file_name)));
         }
@@ -282,7 +282,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="data">Data</param>
         /// <param name="subfolder_name">Archive file name (HH_mm_ss_fff_counter.{ext} by default)</param>
         /// <returns></returns>
-        public void StoreData(byte[] data, string subfolder_name = null, string file_name = null)
+        public void StoreData(byte[] data, string subfolder_name = null!, string file_name = null!)
         {
             Apply(new StoreData(data, CreateArchiveFilePath(subfolder_name, file_name)));
         }
@@ -410,7 +410,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="text">Text</param>
         /// <param name="name">Archive file name (HH_mm_ss_fff_counter.{ext} by default)</param>
         /// <returns></returns>
-        public void StoreText(string text, string name = null)
+        public void StoreText(string text, string name = null!)
         {
             Apply(new StoreText(text, CreateArchiveFilePath(name)));
         }
@@ -421,7 +421,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="file_path">File path</param>
         /// <param name="subfolder_name">Archive file name (original file name by default)</param>
         /// <returns></returns>
-        public void Store(string file_path, string name = null)
+        public void Store(string file_path, string name = null!)
         {
             Apply(new StoreFile(file_path, CreateArchiveFilePath(name)));
         }
@@ -432,7 +432,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="file_path">File path</param>
         /// <param name="subfolder_name">Archive file name (original file name by default)</param>
         /// <returns></returns>
-        public void Store(string file_path, bool immediate, string name = null)
+        public void Store(string file_path, bool immediate, string name = null!)
         {
             if (immediate)
             {
@@ -450,7 +450,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="stream">Data stream for reading</param>
         /// <param name="name">Archive file name (HH_mm_ss_fff_counter.{ext} by default)</param>
         /// <returns></returns>
-        public void Store(Stream stream, string name = null)
+        public void Store(Stream stream, string name = null!)
         {
             Apply(new StoreStream(stream, CreateArchiveFilePath(name)));
         }
@@ -461,7 +461,7 @@ namespace ZeroLevel.Services.FileSystem
         /// <param name="data">Data</param>
         /// <param name="name">Archive file name (HH_mm_ss_fff_counter.{ext} by default)</param>
         /// <returns></returns>
-        public void StoreData(byte[] data, string name = null)
+        public void StoreData(byte[] data, string name = null!)
         {
             Apply(new StoreData(data, CreateArchiveFilePath(name)));
         }

ZeroLevel/Services/FileSystem/PeriodicFileSystemWatcher.cs

@@ -24,7 +24,7 @@ namespace ZeroLevel.Services.FileSystem
         private readonly bool _useSubdirectories = false;
 
         public PeriodicFileSystemWatcher(TimeSpan period, string watch_folder, string temp_folder, Action<FileMeta> callback
-            , IEnumerable<string> extensions = null
+            , IEnumerable<string> extensions = null!
             , bool removeTempFileAfterCallback = false
             , bool useSubdirectories = false)
         {
@@ -32,7 +32,7 @@ namespace ZeroLevel.Services.FileSystem
             {
                 throw new ArgumentNullException(nameof(watch_folder));
             }
-            if (callback == null)
+            if (callback == null!)
             {
                 throw new ArgumentNullException(nameof(callback));
             }
@@ -141,7 +141,7 @@ namespace ZeroLevel.Services.FileSystem
         /// </summary>
         private string MoveToTemporary(string from)
         {
-            if (from == null)
+            if (from == null!)
             {
                 throw new ArgumentException("from");
             }
@@ -156,7 +156,7 @@ namespace ZeroLevel.Services.FileSystem
                 File.Delete(from);
                 return tempFile;
             }
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -164,14 +164,14 @@ namespace ZeroLevel.Services.FileSystem
         /// </summary>
         private static string TrySolveCollision(string file)
         {
-            if (file == null)
+            if (file == null!)
             {
                 throw new ArgumentNullException("file");
             }
             string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(file);
             string extension = Path.GetExtension(file);
             string directoryName = Path.GetDirectoryName(file);
-            if (directoryName != null)
+            if (directoryName != null!)
             {
                 int num = 0;
                 do
@@ -200,17 +200,17 @@ namespace ZeroLevel.Services.FileSystem
             {
                 files = Directory.GetFiles(_sourceFolder, "*.*", _useSubdirectories ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly)
                     ?.Where(f => _extensions.Contains(Path.GetExtension(f).ToLowerInvariant()))
-                    ?.ToArray();
+                    ?.ToArray()!;
             }
             else
             {
                 files = Directory.GetFiles(_sourceFolder, "*.*", _useSubdirectories ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly);
             }
-            if (files != null)
+            if (files != null!)
             {
                 Array.Sort<string>(files, FileNameSortCompare);
             }
-            return files;
+            return files!;
         }
 
         /// <summary>

ZeroLevel/Services/HashFunctions/StringHash.cs

@@ -12,7 +12,7 @@
             {
                 int hash1 = (5381 << 16) + 5381;
                 int hash2 = hash1;
-                if (str != null)
+                if (str != null!)
                 {
                     for (int i = 0; i < str.Length; i += 2)
                     {

ZeroLevel/Services/IL.cs

@@ -48,7 +48,7 @@ namespace ZeroLevel.Services
             // Поле для хранения метода обратного вызова
             _callbackField = _typeBuilder.DefineField("_callbackHandler", CreateDecorateMethodCallHandlerDelegate(_moduleBuilder), FieldAttributes.Private);
             _interfaces = interfaces;
-            _parentType = parentType;
+            _parentType = parentType!;
         }
         /// <summary>
         /// Собирает конечный тип
@@ -105,7 +105,7 @@ namespace ZeroLevel.Services
                 list.AddRange(_interfaces);
                 list.AddRange(GetInterfaces(_interfaces));
             }
-            if (_parentType != null)
+            if (_parentType != null!)
             {
                 list.AddRange(GetInterfaces(new Type[] { _parentType }));
             }
@@ -152,7 +152,7 @@ namespace ZeroLevel.Services
         /// </summary>
         private void ProceedParentAbstractMethods()
         {
-            if (_parentType != null)
+            if (_parentType != null!)
             {
                 foreach (var method in _parentType.GetMethods())
                 {

ZeroLevel/Services/Invokation/InvokeWrapper.cs

@@ -109,6 +109,7 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.Public |
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Select(CreateCompiledExpression);
+            if (result == null) return Enumerable.Empty<string>();
             Configure(result);
             return result.Select(r => r.Item1).ToList();
         }
@@ -121,6 +122,7 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(m => m.Name.Equals(methodName))
                 ?.Select(CreateCompiledExpression);
+            if (result == null) return Enumerable.Empty<string>();
             Configure(result);
             return result.Select(r => r.Item1).ToList();
         }
@@ -133,6 +135,7 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(m => m.Name.Equals(methodName))
                 ?.Select(method => method.MakeGenericMethod(typeof(T))).Select(CreateCompiledExpression);
+            if (result == null) return Enumerable.Empty<string>();
             Configure(result);
             return result.Select(r => r.Item1).ToList();
         }
@@ -145,6 +148,7 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(m => m.Name.Equals(methodName))
                 ?.Select(method => method.MakeGenericMethod(genericType)).Select(CreateCompiledExpression);
+            if (result == null) return Enumerable.Empty<string>();
             Configure(result);
             return result.Select(r => r.Item1).ToList();
         }
@@ -157,12 +161,9 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(filter)
                 ?.Select(method => method.MakeGenericMethod(typeof(T))).Select(CreateCompiledExpression);
-            if (result != null)
+            if (result == null) return Enumerable.Empty<string>();
-            {
+            Configure(result);
-                Configure(result);
+            return result.Select(r => r.Item1).ToList();
-                return result.Select(r => r.Item1).ToList();
-            }
-            return Enumerable.Empty<string>();
         }
 
         public IEnumerable<string> ConfigureGeneric(Type instanceType, Type genericType, Func<MethodInfo, bool> filter)
@@ -173,12 +174,9 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(filter)
                 ?.Select(method => method.MakeGenericMethod(genericType)).Select(CreateCompiledExpression);
-            if (result != null)
+            if (result == null) return Enumerable.Empty<string>();
-            {
+            Configure(result);
-                Configure(result);
+            return result.Select(r => r.Item1).ToList();
-                return result.Select(r => r.Item1).ToList();
-            }
-            return Enumerable.Empty<string>();
         }
 
         public IEnumerable<string> Configure(Type instanceType, Func<MethodInfo, bool> filter)
@@ -189,12 +187,9 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(filter)
                 ?.Select(CreateCompiledExpression);
-            if (result != null)
+            if (result == null) return Enumerable.Empty<string>();
-            {
+            Configure(result);
-                Configure(result);
+            return result.Select(r => r.Item1).ToList();
-                return result.Select(r => r.Item1).ToList();
-            }
-            return Enumerable.Empty<string>();
         }
 
         #endregion Configure by Type
@@ -274,7 +269,7 @@ namespace ZeroLevel.Services.Invokation
         {
             if (_invokeCachee.ContainsKey(identity))
             {
-                return _invokeCachee[identity](null, args);
+                return _invokeCachee[identity](null!, args);
             }
 
             throw new KeyNotFoundException(String.Format("Not found method with identity '{0}'", identity));
@@ -301,7 +296,7 @@ namespace ZeroLevel.Services.Invokation
         {
             if (_invokeCachee.ContainsKey(identity))
             {
-                return _invokeCachee[identity](target, null);
+                return _invokeCachee[identity](target, null!);
             }
 
             throw new KeyNotFoundException($"Not found method with identity '{identity}'");
@@ -345,7 +340,7 @@ namespace ZeroLevel.Services.Invokation
                 return _invokeCachee[identity];
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>

ZeroLevel/Services/Logging/Implementation/EncryptedFileLog.cs

@@ -10,7 +10,7 @@ namespace ZeroLevel.Logging
     {
         public EncryptedFileLogOptions()
         {
-            Folder = null;
+            Folder = null!;
             LimitFileSize = 0;
         }
 
@@ -77,7 +77,7 @@ namespace ZeroLevel.Logging
 
         public EncryptedFileLog(EncryptedFileLogOptions options)
         {
-            if (options == null)
+            if (options == null!)
                 throw new ArgumentNullException(nameof(options));
             if (string.IsNullOrEmpty(options.Key))
                 throw new ArgumentNullException("options.Key");
@@ -120,7 +120,7 @@ namespace ZeroLevel.Logging
                 }
                 catch
                 {
-                    if (stream != null)
+                    if (stream != null!)
                     {
                         stream.Dispose();
                     }
@@ -134,10 +134,10 @@ namespace ZeroLevel.Logging
         /// </summary>
         private void CloseCurrentWriter()
         {
-            if (_writer != null)
+            if (_writer != null!)
             {
                 _writer.Dispose();
-                _writer = null;
+                _writer = null!;
             }
         }
 

ZeroLevel/Services/Logging/Implementation/TextFileLogger.cs

@@ -13,7 +13,7 @@ namespace ZeroLevel.Logging
     {
         public TextFileLoggerOptions()
         {
-            Folder = null;
+            Folder = null!;
             LimitFileSize = 0;
             TextEncoding = DEFAULT_ENCODING;
             RemoveOlderThen = TimeSpan.MinValue;
@@ -211,7 +211,7 @@ namespace ZeroLevel.Logging
                             file.Delete();
                         }
                     });
-                dir = null;
+                dir = null!;
             }
             catch { }
         }
@@ -221,12 +221,12 @@ namespace ZeroLevel.Logging
         /// </summary>
         private void CloseCurrentWriter()
         {
-            if (_writer != null)
+            if (_writer != null!)
             {
                 _writer.Flush();
                 _writer.Close();
                 _writer.Dispose();
-                _writer = null;
+                _writer = null!;
             }
         }
 
@@ -266,7 +266,7 @@ namespace ZeroLevel.Logging
             {
                 RecreateLogFile();
             }
-            fi = null;
+            fi = null!;
         }
 
         /// <summary>
@@ -278,18 +278,18 @@ namespace ZeroLevel.Logging
             {
                 var nextFileName = GetNextFileName();
                 CloseCurrentWriter();
-                Stream stream = null;
+                Stream stream = null!;
                 PackOldLogFile(_currentLogFile);
                 try
                 {
                     _currentLogFile = nextFileName;
                     stream = new FileStream(_currentLogFile, FileMode.Append, FileAccess.Write, FileShare.Read);
                     _writer = new StreamWriter(stream, _options.TextEncoding);
-                    stream = null;
+                    stream = null!;
                 }
                 catch
                 {
-                    if (stream != null)
+                    if (stream != null!)
                     {
                         stream.Dispose();
                     }
@@ -316,7 +316,7 @@ namespace ZeroLevel.Logging
                             }
                             reader.Close();
                         }
-                        buffer = null;
+                        buffer = null!;
                     }
                     stream.Close();
                 }
@@ -419,27 +419,27 @@ namespace ZeroLevel.Logging
         /// </summary>
         private void CloseCurrentWriter()
         {
-            if (_writer != null)
+            if (_writer != null!)
             {
                 _writer.Flush();
                 _writer.Close();
                 _writer.Dispose();
-                _writer = null;
+                _writer = null!;
             }
         }
 
         private void CreateLogFile(string path)
         {
-            Stream stream = null;
+            Stream stream = null!;
             try
             {
                 stream = new FileStream(path, FileMode.Append, FileAccess.Write, FileShare.Read);
                 _writer = new StreamWriter(stream, DEFAULT_ENCODING);
-                stream = null;
+                stream = null!;
             }
             catch
             {
-                if (stream != null)
+                if (stream != null!)
                 {
                     stream.Dispose();
                 }

ZeroLevel/Services/Logging/Log.cs

@@ -206,7 +206,7 @@ namespace ZeroLevel
             {
                 return;
             }
-            string logPath = null;
+            string logPath = null!;
             if (config.Contains("log"))
             {
                 logPath = config.First("log");
@@ -218,7 +218,7 @@ namespace ZeroLevel
             if (false == string.IsNullOrWhiteSpace(logPath))
             {
                 var options = TextFileLoggerOptions.CreateOptionsBy(config, logPath, log_section ? string.Empty : "log.");
-                if (options != null)
+                if (options != null!)
                 {
                     AddTextFileLogger(options);
                 }

ZeroLevel/Services/Logging/LogRouterr.cs

@@ -53,7 +53,7 @@ namespace ZeroLevel.Logging
                     _messageQueue.Push(t.Item1, t.Item2);
                 }
                 currentQueue.Dispose();
-                currentQueue = null;
+                currentQueue = null!;
                 GC.Collect();
                 GC.WaitForFullGCComplete();
             }
@@ -64,7 +64,7 @@ namespace ZeroLevel.Logging
             while (false == _stopped || _messageQueue.Count > 0)
             {
                 var message = _messageQueue.Take();
-                if (message != null)
+                if (message != null!)
                 {
                     lock (LogsCacheeLocker)
                     {
@@ -79,7 +79,7 @@ namespace ZeroLevel.Logging
                             }
                         }
                     }
-                    message = null;
+                    message = null!;
                 }
             }
         }

ZeroLevel/Services/Mathemathics/Histogram.cs

@@ -74,7 +74,7 @@ namespace ZeroLevel.Mathemathics
         {
             if ((Values?.Length ?? 0) <= 2) return 0;
             int i = 0;
-            while (Values[i] <= float.Epsilon) { i++; continue; }
+            while (Values![i] <= float.Epsilon) { i++; continue; }
             if ((Values.Length - i) <= 2) return 0;
 
             var delta = Values[i + 1] - Values[i];
@@ -112,7 +112,7 @@ namespace ZeroLevel.Mathemathics
 
             if ((Values?.Length ?? 0) <= 2) return list;
             int i = 0;
-            while (Values[i] <= float.Epsilon) { i++; continue; }
+            while (Values![i] <= float.Epsilon) { i++; continue; }
             if ((Values.Length - i) <= 2) return list;
 
             var delta = Values[i + 1] - Values[i];
@@ -144,12 +144,12 @@ namespace ZeroLevel.Mathemathics
 
         public int GetMaximum()
         {
-            if ((Values?.Length ?? 0) <= 1) return Values[0];
+            if ((Values?.Length ?? 0) <= 1) return Values![0]!;
             int maxi = 0;
             int max = 0;
-            for (int i = 0; i < Values.Length; i++)
+            for (int i = 0; i < (Values?.Length ?? 0); i++)
             {
-                if (Values[i] > max)
+                if (Values![i] > max)
                 {
                     max = Values[i];
                     maxi = i;

ZeroLevel/Services/Memory/MMFViewAccessor.cs

@@ -34,7 +34,7 @@ namespace ZeroLevel.Services.Memory
 
         public async Task<byte[]> ReadBuffer(int count)
         {
-            if (count == 0) return null;
+            if (count == 0) return null!;
             var buffer = new byte[count];
             var readedCount = await _accessor.ReadAsync(buffer, 0, count);
             if (count != readedCount)

ZeroLevel/Services/Memory/StreamVewAccessor.cs

@@ -25,7 +25,7 @@ namespace ZeroLevel.Services.Memory
 
         public async Task<byte[]> ReadBuffer(int count)
         {
-            if (count == 0) return null;
+            if (count == 0) return null!;
             var buffer = new byte[count];
             var readedCount = await _stream.ReadAsync(buffer, 0, count);
             if (count != readedCount)

ZeroLevel/Services/MemoryPools/Collections/Linq/Aggregate.cs

@@ -6,12 +6,12 @@ namespace MemoryPools.Collections.Linq
     {
         public static TSource Aggregate<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, TSource, TSource> func)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (func == null)
+            if (func == null!)
             {
                 throw new ArgumentNullException(nameof(func));
             }
@@ -34,12 +34,12 @@ namespace MemoryPools.Collections.Linq
 
         public static TAccumulate Aggregate<TSource, TAccumulate>(this IPoolingEnumerable<TSource> source, TAccumulate seed, Func<TAccumulate, TSource, TAccumulate> func)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (func == null)
+            if (func == null!)
             {
                 throw new ArgumentNullException(nameof(func));
             }
@@ -55,17 +55,17 @@ namespace MemoryPools.Collections.Linq
 
         public static TResult Aggregate<TSource, TAccumulate, TResult>(this IPoolingEnumerable<TSource> source, TAccumulate seed, Func<TAccumulate, TSource, TAccumulate> func, Func<TAccumulate, TResult> resultSelector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (func == null)
+            if (func == null!)
             {
                 throw new ArgumentNullException(nameof(func));
             }
 
-            if (resultSelector == null)
+            if (resultSelector == null!)
             {
                 throw new ArgumentNullException(nameof(resultSelector));
             }

ZeroLevel/Services/MemoryPools/Collections/Linq/Append.Enumerable.cs

@@ -27,8 +27,8 @@
             _count--;
             if (_count == 0)
             {
-                _src = default;
+                _src = default!;
-                _element = default;
+                _element = default!;
                 Pool<AppendExprEnumerable<T>>.Return(this);
             }
         }
@@ -72,16 +72,16 @@
                 _src.Reset();
             }
 
-            object IPoolingEnumerator.Current => Current;
+            object IPoolingEnumerator.Current => Current!;
 
             public T Current => _overcount == 1 ? _element : (T) _src.Current;
 
             public void Dispose()
             {
                 _parent?.Dispose();
-                _parent = null;
+                _parent = null!;
                 _src?.Dispose();
-                _src = default;
+                _src = default!;
                 Pool<AppendExprEnumerator>.Return(this);
             }
         }

ZeroLevel/Services/MemoryPools/Collections/Linq/Average.cs

@@ -9,7 +9,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double Average(this IPoolingEnumerable<int> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -41,7 +41,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double? Average(this IPoolingEnumerable<int?> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -73,7 +73,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -81,7 +81,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double Average(this IPoolingEnumerable<long> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -113,7 +113,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double? Average(this IPoolingEnumerable<long?> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -145,7 +145,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -153,7 +153,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static float Average(this IPoolingEnumerable<float> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -182,7 +182,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static float? Average(this IPoolingEnumerable<float?> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -214,7 +214,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -222,7 +222,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double Average(this IPoolingEnumerable<double> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -254,7 +254,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double? Average(this IPoolingEnumerable<double?> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -286,7 +286,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -294,7 +294,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static decimal Average(this IPoolingEnumerable<decimal> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -323,7 +323,7 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static decimal? Average(this IPoolingEnumerable<decimal?> source)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
@@ -352,7 +352,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -360,12 +360,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, int> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -397,12 +397,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double? Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, int?> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -434,7 +434,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -442,12 +442,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, long> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -479,12 +479,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double? Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, long?> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -516,7 +516,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -524,12 +524,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static float Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, float> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -558,12 +558,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static float? Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, float?> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -595,7 +595,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -603,12 +603,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, double> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -640,12 +640,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static double? Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, double?> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -677,7 +677,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
 
         /// <summary>
@@ -685,12 +685,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static decimal Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, decimal> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -719,12 +719,12 @@ namespace MemoryPools.Collections.Linq
         /// </summary>
         public static decimal? Average<TSource>(this IPoolingEnumerable<TSource> source, Func<TSource, decimal?> selector)
         {
-            if (source == null)
+            if (source == null!)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
-            if (selector == null)
+            if (selector == null!)
             {
                 throw new ArgumentNullException(nameof(selector));
             }
@@ -753,7 +753,7 @@ namespace MemoryPools.Collections.Linq
                 }
             }
 
-            return null;
+            return null!;
         }
     }
 }

ZeroLevel/Services/MemoryPools/Collections/Linq/Cast.Enumerable.cs

@@ -25,7 +25,7 @@
             _count--;
             if (_count == 0)
             {
-                _src = default;
+                _src = default!;
                 Pool<CastExprEnumerable<T>>.Return(this);
             }
         }
@@ -52,16 +52,16 @@
                 _src.Reset();
             }
 
-            object IPoolingEnumerator.Current => Current;
+            object IPoolingEnumerator.Current => Current!;
 
             public T Current => (T)_src.Current;
 
             public void Dispose()
             {
                 _parent?.Dispose();
-                _parent = null;
+                _parent = null!;
                 _src?.Dispose();
-                _src = default;
+                _src = default!;
                 Pool<CastExprEnumerator>.Return(this);
             }
         }

ZeroLevel/Services/MemoryPools/Collections/Linq/Concat.Enumerable.cs

@@ -25,8 +25,8 @@
             _count--;
             if (_count == 0)
             {
-                _src = default;
+                _src = default!;
-                _second = default;
+                _second = default!;
                 Pool<ConcatExprEnumerable<T>>.Return(this);
             }
         }
@@ -69,18 +69,18 @@
                 _second.Reset();
             }
 
-            object IPoolingEnumerator.Current => Current;
+            object IPoolingEnumerator.Current => Current!;
 
             public T Current => _first ? _src.Current : _second.Current;
 
             public void Dispose()
             {
                 _parent?.Dispose();
-                _parent = default;
+                _parent = default!;
                 _src?.Dispose();
-                _src = default;
+                _src = default!;
                 _second?.Dispose();
-                _second = default;
+                _second = default!;
                 Pool<ConcatExprEnumerator>.Return(this);
             }
         }

ZeroLevel/Services/MemoryPools/Collections/Linq/Distinct.Enumerable.cs

@@ -11,7 +11,7 @@ namespace MemoryPools.Collections.Linq
         private IEqualityComparer<TItem> _comparer;
         private Func<T, TItem> _selector;
 
-        public DistinctExprEnumerable<T, TItem> Init(IPoolingEnumerator<T> parent, Func<T, TItem> selector, IEqualityComparer<TItem> comparer  = default)
+        public DistinctExprEnumerable<T, TItem> Init(IPoolingEnumerator<T> parent, Func<T, TItem> selector, IEqualityComparer<TItem> comparer  = default!)
         {
             _parent = parent;
             _selector = selector;
@@ -33,8 +33,8 @@ namespace MemoryPools.Collections.Linq
             if (_count == 0)
             {
                 _parent?.Dispose();
-                _parent = default;
+                _parent = default!;
-                _selector = default;
+                _selector = default!;
                 Pool<DistinctExprEnumerable<T, TItem>>.Return(this);
             }
         }

ZeroLevel/Services/MemoryPools/Collections/Linq/Except.Enumerable.cs

@@ -10,7 +10,7 @@ namespace MemoryPools.Collections.Linq
         private IEqualityComparer<T> _comparer;
         private PoolingDictionary<T, int> _except;
 
-        public ExceptExprEnumerable<T> Init(IPoolingEnumerable<T> src, PoolingDictionary<T, int> except, IEqualityComparer<T> comparer  = default)
+        public ExceptExprEnumerable<T> Init(IPoolingEnumerable<T> src, PoolingDictionary<T, int> except, IEqualityComparer<T> comparer  = default!)
         {
             _src = src;
             _except = except;
@@ -31,11 +31,11 @@ namespace MemoryPools.Collections.Linq
             _count--;
             if (_count == 0)
             {
-                _src = default;
+                _src = default!;
                 _except?.Dispose();
-                Pool<PoolingDictionary<T, int>>.Return(_except);
+                Pool<PoolingDictionary<T, int>>.Return(_except!);
-                _except = default;
+                _except = default!;
-                Pool<ExceptExprEnumerable<T>>.Return(this);
+                Pool<ExceptExprEnumerable<T>>.Return(this!);
             }
         }
         internal class ExceptExprEnumerator : IPoolingEnumerator<T>
@@ -63,17 +63,17 @@ namespace MemoryPools.Collections.Linq
 
             public void Reset() => _src.Reset();
 
-            object IPoolingEnumerator.Current => Current;
+            object IPoolingEnumerator.Current => Current!;
 
             public T Current => _src.Current;
 
             public void Dispose()
             {
                 _src?.Dispose();
-                _src = null;
+                _src = null!;
                 
                 _parent?.Dispose();
-                _parent = default;
+                _parent = default!;
                 
                 Pool<ExceptExprEnumerator>.Return(this);
             }

ZeroLevel/Services/MemoryPools/Collections/Linq/FirstFirstOrDefault.cs

@@ -65,10 +65,10 @@ namespace MemoryPools.Collections.Linq
             var enumerator = source.GetEnumerator();
             var hasItem = enumerator.MoveNext();
 
-            var item= hasItem ? enumerator.Current : default;
+            var item = hasItem ? enumerator.Current : default;
             enumerator.Dispose();
 
-            return item;
+            return item!;
         }
 
         /// <summary>
@@ -86,7 +86,7 @@ namespace MemoryPools.Collections.Linq
                 return elem;
             }
             enumerator.Dispose();
-            return default;
+            return default!;
         }
 
         /// <summary>
@@ -104,7 +104,7 @@ namespace MemoryPools.Collections.Linq
                 return elem;
             }
             enumerator.Dispose();
-            return default;
+            return default!;
         }
     }
 }

ZeroLevel/Services/MemoryPools/Collections/Linq/GenericEnumerable.cs

@@ -16,7 +16,7 @@ namespace MemoryPools.Collections.Linq
 		public IPoolingEnumerator<T> GetEnumerator()
 		{
 			var enumerator = _enumerable.GetEnumerator();
-			_enumerable = default;
+			_enumerable = default!;
 			Pool<GenericPoolingEnumerable<T>>.Return(this);
 			return Pool<GenericPoolingEnumerator<T>>.Get().Init(enumerator);
 		}
@@ -39,7 +39,7 @@ namespace MemoryPools.Collections.Linq
 		public IEnumerator<T> GetEnumerator()
 		{
 			var enumerator = _enumerable.GetEnumerator();
-			_enumerable = default;
+			_enumerable = default!;
 			Pool<GenericEnumerable<T>>.Return(this);
 			return Pool<GenericEnumerator<T>>.Get().Init(enumerator);
 		}

ZeroLevel/Services/MemoryPools/Collections/Linq/GenericPoolingEnumerator.cs

@@ -17,14 +17,14 @@ namespace MemoryPools.Collections.Linq
 
 		public void Reset() => _source.Reset();
 		
-		object IPoolingEnumerator.Current => Current;
+		object IPoolingEnumerator.Current => Current!;
 
 		public T Current => _source.Current;
     
 		public void Dispose()
 		{
 			_source.Dispose();
-			_source = default;
+			_source = default!;
 			Pool<GenericPoolingEnumerator<T>>.Return(this);
 		}
 	}
@@ -43,14 +43,14 @@ namespace MemoryPools.Collections.Linq
 
 		public void Reset() => _source.Reset();
 		
-		object IEnumerator.Current => Current;
+		object IEnumerator.Current => Current!;
 
 		public T Current => _source.Current;
     
 		public void Dispose()
 		{
 			_source.Dispose();
-			_source = default;
+			_source = default!;
 			Pool<GenericEnumerator<T>>.Return(this);
 		}
 	}

ZeroLevel/Services/MemoryPools/Collections/Linq/GroupBy.Enumerable.cs

@@ -53,9 +53,9 @@ namespace MemoryPools.Collections.Linq
             
             if (_count == 0)
             {
-                _comparer = default;
+                _comparer = default!;
-                _elementSelector = default;
+                _elementSelector = default!;
-                _keySelector = default;
+                _keySelector = default!;
                 Pool<GroupedEnumerable<TSource, TKey, TElement>>.Return(this);
             }
         }
@@ -89,16 +89,16 @@ namespace MemoryPools.Collections.Linq
                 
                 // cleanup collection
                 _src?.Dispose();
-                Pool<PoolingDictionary<TKey, PoolingGrouping>>.Return(_src);
+                Pool<PoolingDictionary<TKey, PoolingGrouping>>.Return(_src!);
-                _src = default;
+                _src = default!;
                 
                 _enumerator?.Dispose();
-                _enumerator = default;
+                _enumerator = default!;
                 
                 _parent?.Dispose();
-                _parent = default;
+                _parent = default!;
                 
-                Pool<PoolingGroupingEnumerator>.Return(this);
+                Pool<PoolingGroupingEnumerator>.Return(this!);
             }
 
             public bool MoveNext() => _enumerator.MoveNext();
@@ -107,7 +107,7 @@ namespace MemoryPools.Collections.Linq
 
             public IPoolingGrouping<TKey, TElement> Current => _enumerator.Current.Value;
 
-            object IPoolingEnumerator.Current => Current;
+            object IPoolingEnumerator.Current => Current!;
         }
 
         internal class PoolingGrouping : IPoolingGrouping<TKey, TElement>, IDisposable
@@ -132,10 +132,10 @@ namespace MemoryPools.Collections.Linq
             public void Dispose()
             {
                 _elements?.Dispose();
-                Pool<PoolingList<TElement>>.Return(_elements);
+                Pool<PoolingList<TElement>>.Return(_elements!);
-                _elements = null;
+                _elements = null!;
                 
-                Key = default;
+                Key = default!;
             }
         }
     }

ZeroLevel/Services/MemoryPools/Collections/Linq/GroupBy.ResultEnumerable.cs

@@ -53,9 +53,9 @@ namespace MemoryPools.Collections.Linq
             
             if (_count == 0)
             {
-                _comparer = default;
+                _comparer = default!;
-                _resultSelector = default;
+                _resultSelector = default!;
-                _keySelector = default;
+                _keySelector = default!;
                 Pool<GroupedResultEnumerable<TSource, TKey, TResult>>.Return(this);
             }
         }
@@ -89,14 +89,14 @@ namespace MemoryPools.Collections.Linq
                 
                 // cleanup collection
                 _src?.Dispose();
-                Pool<PoolingDictionary<TKey, PoolingGrouping>>.Return(_src);
+                Pool<PoolingDictionary<TKey, PoolingGrouping>>.Return(_src!);
-                _src = default;
+                _src = default!;
                 
                 _enumerator?.Dispose();
-                _enumerator = default;
+                _enumerator = default!;
                 
                 _parent?.Dispose();
-                _parent = default;
+                _parent = default!;
                 
                 Pool<GroupedResultEnumerator>.Return(this);
             }
@@ -107,7 +107,7 @@ namespace MemoryPools.Collections.Linq
 
             public TResult Current => _parent._resultSelector(_enumerator.Current.Key, _enumerator.Current.Value.InternalList);
 
-            object IPoolingEnumerator.Current => Current;
+            object IPoolingEnumerator.Current => Current!;
         }
 
         internal class PoolingGrouping : IPoolingGrouping<TKey, TSource>, IDisposable
@@ -132,10 +132,10 @@ namespace MemoryPools.Collections.Linq
             public void Dispose()
             {
                 _elements?.Dispose();
-                Pool<PoolingList<TSource>>.Return(_elements);
+                Pool<PoolingList<TSource>>.Return(_elements!);
-                _elements = null;
+                _elements = null!;
                 
-                Key = default;
+                Key = default!;
             }
         }
     }

ZeroLevel/Services/MemoryPools/Collections/Linq/GroupBy.cs

@@ -6,19 +6,19 @@ namespace MemoryPools.Collections.Linq
     public static partial class PoolingEnumerable
     {
         public static IPoolingEnumerable<IPoolingGrouping<TKey, TSource>> GroupBy<TSource, TKey>(this IPoolingEnumerable<TSource> source, Func<TSource, TKey> keySelector) =>
-            Pool<GroupedEnumerable<TSource, TKey, TSource>>.Get().Init(source, keySelector, x => x, null);
+            Pool<GroupedEnumerable<TSource, TKey, TSource>>.Get().Init(source, keySelector, x => x, null!);
         
         public static IPoolingEnumerable<IPoolingGrouping<TKey, TSource>> GroupBy<TSource, TKey>(this IPoolingEnumerable<TSource> source, Func<TSource, TKey> keySelector, IEqualityComparer<TKey> comparer) =>
             Pool<GroupedEnumerable<TSource, TKey, TSource>>.Get().Init(source, keySelector, x => x, comparer);
 
         public static IPoolingEnumerable<IPoolingGrouping<TKey, TElement>> GroupBy<TSource, TKey, TElement>(this IPoolingEnumerable<TSource> source, Func<TSource, TKey> keySelector, Func<TSource, TElement> elementSelector) =>
-            Pool<GroupedEnumerable<TSource, TKey, TElement>>.Get().Init(source, keySelector, elementSelector, null);
+            Pool<GroupedEnumerable<TSource, TKey, TElement>>.Get().Init(source, keySelector, elementSelector, null!);
 
         public static IPoolingEnumerable<IPoolingGrouping<TKey, TElement>> GroupBy<TSource, TKey, TElement>(this IPoolingEnumerable<TSource> source, Func<TSource, TKey> keySelector, Func<TSource, TElement> elementSelector, IEqualityComparer<TKey> comparer) =>
             Pool<GroupedEnumerable<TSource, TKey, TElement>>.Get().Init(source, keySelector, elementSelector, comparer);
 
         public static IPoolingEnumerable<TResult> GroupBy<TSource, TKey, TResult>(this IPoolingEnumerable<TSource> source, Func<TSource, TKey> keySelector, Func<TKey, IPoolingEnumerable<TSource>, TResult> resultSelector) =>
-            Pool<GroupedResultEnumerable<TSource, TKey, TResult>>.Get().Init(source, keySelector, resultSelector, null);
+            Pool<GroupedResultEnumerable<TSource, TKey, TResult>>.Get().Init(source, keySelector, resultSelector, null!);
         
         // public static IPoolingEnumerable<TResult> GroupBy<TSource, TKey, TElement, TResult>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector, Func<TSource, TElement> elementSelector, Func<TKey, IEnumerable<TElement>, TResult> resultSelector) =>
         //     new GroupedResultEnumerable<TSource, TKey, TElement, TResult>(source, keySelector, elementSelector, resultSelector, null);

ZeroLevel/Services/MemoryPools/Collections/Linq/Intersect.Enumerable.cs

@@ -13,7 +13,7 @@ namespace MemoryPools.Collections.Linq
         public IntersectExprEnumerable<T> Init(
             IPoolingEnumerable<T> src,
             PoolingDictionary<T, int> second,
-            IEqualityComparer<T> comparer = default)
+            IEqualityComparer<T> comparer = default!)
         {
             _src = src;
             _count = 0;
@@ -34,11 +34,11 @@ namespace MemoryPools.Collections.Linq
             _count--;
             if (_count == 0)
             {
-                _src = default;
+                _src = default!;
                 _second?.Dispose();
-                Pool<PoolingDictionary<T, int>>.Return(_second);
+                Pool<PoolingDictionary<T, int>>.Return(_second!);
 
-                _second = default;
+                _second = default!;
                 Pool<IntersectExprEnumerable<T>>.Return(this);
             }
         }
@@ -74,23 +74,23 @@ namespace MemoryPools.Collections.Linq
 
             public void Reset() => _src.Reset();
 
-            object IPoolingEnumerator.Current => Current;
+            object IPoolingEnumerator.Current => Current!;
 
             public T Current => _src.Current;
 
             public void Dispose()
             {
                 _src?.Dispose();
-                _src = null;
+                _src = null!;
                 
                 _alreadyDoneItems?.Dispose();
-                Pool<PoolingDictionary<T, int>>.Return(_alreadyDoneItems);
+                Pool<PoolingDictionary<T, int>>.Return(_alreadyDoneItems!);
-                _alreadyDoneItems = default;
+                _alreadyDoneItems = default!;
                 
                 _parent?.Dispose();
-                _parent = default;
+                _parent = default!;
                 
-                Pool<IntersectExprEnumerator>.Return(this);
+                Pool<IntersectExprEnumerator>.Return(this!);
             }
         }
         IPoolingEnumerator IPoolingEnumerable.GetEnumerator() => GetEnumerator();