Append Sleopok engine

Apps/ZeroLevel.Discovery/ZeroLevel.Discovery.csproj

@@ -12,7 +12,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\ZeroLevel\ZeroLevel.csproj" />
+    <ProjectReference Include="..\..\ZeroLevel\ZeroLevel.csproj" />
   </ItemGroup>
 
 </Project>

Apps/ZeroLevel.Logger/ZeroLevel.Logger.csproj

@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\ZeroLevel\ZeroLevel.csproj" />
+    <ProjectReference Include="..\..\ZeroLevel\ZeroLevel.csproj" />
   </ItemGroup>
 
 </Project>

Apps/ZeroNetworkMonitor/ZeroNetworkMonitor.csproj

@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\ZeroLevel\ZeroLevel.csproj" />
+    <ProjectReference Include="..\..\ZeroLevel\ZeroLevel.csproj" />
   </ItemGroup>
 
   <ItemGroup>

Tests/Sleopok.Tests/Program.cs

@@ -0,0 +1,141 @@
+using ZeroLevel.Services.Semantic;
+using ZeroLevel.Services.Serialization;
+using ZeroLevel.Sleopok.Engine;
+using ZeroLevel.Sleopok.Engine.Models;
+using ZeroLevel.Sleopok.Engine.Services;
+using ZeroLevel.Sleopok.Engine.Services.Storage;
+
+namespace Sleopok.Tests
+{
+    internal class Program
+    {
+        public sealed class BookDocument
+        {
+            public string Id { get; set; }
+
+            [SleoIndex("title", 200.0f)]
+            public string Title { get; set; }
+
+            [SleoIndex("titlelm", 100.0f)]
+            public string TitleLemmas { get; set; }
+
+            [SleoIndex("author", 10.0f)]
+            public string Author { get; set; }
+
+            [SleoIndex("genre", 1.0f)]
+            public string Genre { get; set; }
+        }
+
+        private static Dictionary<string, string> _titles = new Dictionary<string, string>
+        {
+            { "66056bc0481e83af64c55022", "Документ без названия" },
+            { "6605698d481e83af64c45ad7", "На развилке дорог. Часть 2"},
+            { "660581bc481e83af64cb8b4d", "Паниклав"},
+            { "66057aa2481e83af64c9bb11", "Князь. Война магов (сборник)"},
+            { "66057f75481e83af64cb04f7", "Антология севетского детектива-8. Компиляция. Книги 1-17"},
+            { "66057bd4481e83af64ca0779", "Вор черной масти"},
+            { "66057247481e83af64c76860", "Выбор"},
+            { "66056807481e83af64c3a64f", "Последняя лекция"},
+            { "66057f13481e83af64caed5d", "Оружие Круппа. История династии пушечных королей"},
+            { "66057a37481e83af64c9a14b", "Месть Черного Дракона"},
+            { "660588e8481e83af64cd2d3e", "Мгла над старыми могилами"},
+            { "66056e88481e83af64c64e81", "Кровь и железо"},
+            { "66057a8e481e83af64c9b673", "Маленькая страна"},
+            { "6605687d481e83af64c3e360", "Санкт-Петербург – история в преданиях и легендах"},
+            { "66057987481e83af64c9770c", "Контракт на рабство"},
+            { "66059052481e83af64cf5e31", "Агент космического сыска"},
+            { "660580f9481e83af64cb61c9", "Две жизни Алессы Коэн"},
+            { "66056807481e84af64c3a64f", "Последняя история"},
+            { "66057f13481e85af64caed5d", "История Китая"},
+            { "66057a37481e86af64c9a14b", "Время Черного Дракона"},
+            { "660588e8481e87af64cd2d3e", "Страна которой нет"},
+        };
+
+        static async Task Main(string[] args)
+        {
+            // TestCompression();
+            // await FillOneFieldIndex();
+            // await TestSearch();
+            await TestEngine();
+        }
+
+        static async Task TestEngine()
+        {
+            var engine = new SleoEngine<BookDocument>(@"H:\Test", b => b.Id);
+            using (var builder = engine.CreateBuilder())
+            {
+                builder.Write(new[]
+                {
+                    new BookDocument{ Id = "01", Title = "Страж птица",  },
+                    new BookDocument{ Id = "02" },
+                    new BookDocument{ Id = "03" },
+                    new BookDocument{ Id = "04" },
+                });
+            }
+        }
+
+        static void TestCompression()
+        {
+            var strings = new string[]
+            {
+                string.Empty,
+                "doc1",
+                "doc2",
+                "",
+                " ",
+                "\r\n",
+                "last",
+                "doc3",
+                "doc4",
+                "doc5",
+                "doc6",
+                "doc7",
+                "doc8",
+                "doc9",
+                "doc10",
+            };
+
+            var clearbytes = MessageSerializer.SerializeCompatible(strings).Length;
+            var compressed = Compressor.Compress(strings);
+            Console.WriteLine($"{compressed.Length} / {clearbytes} bytes");
+
+            var decomressed = Compressor.DecompressToDocuments(compressed);
+            int index = 0;
+            foreach (var s in decomressed)
+            {
+                if (!(string.IsNullOrEmpty(s) && string.IsNullOrEmpty(strings[index])) && 0 != string.CompareOrdinal(strings[index], s))
+                {
+                    Console.WriteLine($"Got {s}. Expected {strings[index]}");
+                }
+                index++;
+            }
+        }
+
+        static async Task FillOneFieldIndex()
+        {
+            var store = new DataStorage(@"H:\TEST");
+            using (var writer = store.GetWriter("title"))
+            {
+                foreach (var kv in _titles)
+                {
+                    var tokens = WordTokenizer.Tokenize(kv.Value);
+                    foreach (var t in tokens)
+                    {
+                        await writer.Write(t, kv.Key);
+                    }
+                }
+                await writer.Complete();
+            }
+        }
+
+        static async Task TestSearch()
+        {
+            var store = new DataStorage(@"H:\TEST");
+            var docs = await store.GetDocuments("title", new string[] { "кровь", "страна", "железо", "история", "оружие" }, 1.0f, false);
+            foreach (var kv in docs.OrderByDescending(kv => kv.Value))
+            {
+                Console.WriteLine($"[{kv.Key}: {kv.Value}] {_titles[kv.Key]}");
+            }
+        }
+    }
+}

Tests/Sleopok.Tests/Sleopok.Tests.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\ZeroLevel.Sleopok.Engine\ZeroLevel.Sleopok.Engine.csproj" />
+  </ItemGroup>
+
+</Project>

ZeroLevel.Sleopok.Engine/Models/IndexInfo.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using ZeroLevel;
+using ZeroLevel.Services.FileSystem;
+using ZeroLevel.Services.Reflection;
+using ZeroLevel.Services.Extensions;
+
+namespace ZeroLevel.Sleopok.Engine.Models
+{
+    internal class IndexInfo<T>
+    {
+        private readonly Func<T, string> _identityExtractor;
+        private readonly List<SleoField> _fields;
+
+        public string GetId(T item) => _identityExtractor.Invoke(item);
+
+        public IReadOnlyCollection<SleoField> Fields => _fields;
+
+        public IndexInfo(Func<T, string> identityExtractor)
+        {
+            _identityExtractor = identityExtractor;
+            _fields = new List<SleoField>();
+            typeof(T).GetMembers(
+                BindingFlags.Public |
+                BindingFlags.FlattenHierarchy |
+                BindingFlags.GetField |
+                BindingFlags.GetProperty |
+                BindingFlags.Instance).
+                Do(members =>
+                {
+                    foreach (var member in members)
+                    {
+                        var sleoAttribute = member.GetCustomAttribute<SleoIndexAttribute>();
+                        if (sleoAttribute == null) continue;
+
+                        Func<object, object> getter;
+                        switch (member.MemberType)
+                        {
+                            case MemberTypes.Field:
+                                getter = TypeGetterSetterBuilder.BuildGetter(member as FieldInfo);
+                                break;
+                            case MemberTypes.Property:
+                                getter = TypeGetterSetterBuilder.BuildGetter(member as PropertyInfo);
+                                break;
+                            default: return;
+                        }
+                        var name = FSUtils.FileNameCorrection(string.IsNullOrWhiteSpace(sleoAttribute.Name) ? member.Name : sleoAttribute.Name);
+                        _fields.Add(new SleoField
+                        {
+                            Boost = sleoAttribute.Boost,
+                            Name = name,
+                            Getter = getter,
+                            ExactMatch = sleoAttribute.AvaliableForExactMatch
+                        });
+                    }
+                });
+        }
+    }
+}

ZeroLevel.Sleopok.Engine/Models/SleoField.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace ZeroLevel.Sleopok.Engine.Models
+{
+    internal sealed class SleoField
+    {
+        public string Name;
+        public float Boost;
+        public bool ExactMatch;
+        public Func<object, object> Getter;
+    }
+}

ZeroLevel.Sleopok.Engine/Models/SleoIndexAttribute.cs

@@ -0,0 +1,19 @@
+using System;
+
+namespace ZeroLevel.Sleopok.Engine.Models
+{
+    public sealed class SleoIndexAttribute
+        : Attribute
+    {
+        public string Name { get; private set; }
+        public float Boost { get; private set; } = 1.0f;
+        public bool AvaliableForExactMatch {  get; private set; } = false;
+        
+        public SleoIndexAttribute(string name, float boost = 1.0f, bool avaliableForExactMatch = false)
+        {
+            Name = name;
+            Boost = boost;
+            AvaliableForExactMatch = avaliableForExactMatch;
+        }
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Compressor.cs

@@ -0,0 +1,57 @@
+using System.IO;
+using System.IO.Compression;
+using ZeroLevel.Services.Serialization;
+
+namespace ZeroLevel.Sleopok.Engine.Services
+{
+    public static class Compressor
+    {
+        private static void CopyTo(Stream src, Stream dest)
+        {
+            byte[] bytes = new byte[4096];
+            int cnt;
+            while ((cnt = src.Read(bytes, 0, bytes.Length)) != 0)
+            {
+                dest.Write(bytes, 0, cnt);
+            }
+        }
+
+        public static byte[] Compress(string[] documents)
+        {
+            return Compress(MessageSerializer.SerializeCompatible(documents));
+        }
+
+        public static string[] DecompressToDocuments(byte[] data)
+        {
+            var bytes = Decompress(data);
+            return MessageSerializer.DeserializeCompatible<string[]>(bytes);
+        }
+
+        public static byte[] Compress(byte[] data)
+        {
+            using (var msi = new MemoryStream(data))
+            using (var mso = new MemoryStream())
+            {
+                using (var gs = new GZipStream(mso, CompressionMode.Compress))
+                {
+                    CopyTo(msi, gs);
+                }
+                return mso.ToArray();
+            }
+        }
+
+        public static byte[] Decompress(byte[] data)
+        {
+            using (var msi = new MemoryStream(data))
+            using (var mso = new MemoryStream())
+            {
+                using (var gs = new GZipStream(msi, CompressionMode.Decompress))
+                {
+                    CopyTo(gs, mso);
+                }
+                return mso.ToArray();
+            }
+        }
+
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Indexes/IIndexBuilder.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace ZeroLevel.Sleopok.Engine.Services.Indexes
+{
+    public interface IIndexBuilder<T>
+        : IDisposable
+    {
+        Task Write(IEnumerable<T> batch);
+        Task Complete();
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Indexes/IIndexReader.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace ZeroLevel.Sleopok.Engine.Services.Indexes
+{
+    public interface IIndexReader<T>
+    {
+        Task<Dictionary<string, float>> Search(string[] tokens, bool exactMatch);
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Indexes/IndexBuilder.cs

@@ -0,0 +1,57 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using ZeroLevel.Sleopok.Engine.Models;
+using ZeroLevel.Sleopok.Engine.Services.Storage;
+
+namespace ZeroLevel.Sleopok.Engine.Services.Indexes
+{
+    internal sealed class IndexBuilder<T>
+        : IIndexBuilder<T>
+    {
+        private readonly DataStorage _storage;
+        private readonly IndexInfo<T> _indexInfo;
+        private readonly Dictionary<string, IPartitionDataWriter> Indexers = new Dictionary<string, IPartitionDataWriter>();
+        public IndexBuilder(DataStorage storage, IndexInfo<T> indexInfo)
+        {
+            _storage = storage;
+            _indexInfo = indexInfo;
+            foreach (var field in indexInfo.Fields)
+            {
+                Indexers[field.Name] = _storage.GetWriter(field.Name);
+            }
+        }
+
+        public async Task Complete()
+        {
+            foreach (var i in Indexers)
+            {
+                await i.Value.Complete();
+                i.Value.Dispose();
+            }
+        }
+
+        public async Task Write(IEnumerable<T> batch)
+        {
+            foreach (var doc in batch)
+            {
+                var doc_id = _indexInfo.GetId(doc);
+                foreach (var field in _indexInfo.Fields)
+                {
+                    var value = field.Getter(doc!)?.ToString() ?? string.Empty;
+                    if (string.IsNullOrWhiteSpace(value) == false)
+                    {
+                        foreach (var t in value.Split(' '))
+                        {
+                            await Indexers[field.Name].Write(t, doc_id);
+                        }
+                    }
+                }
+            }
+        }
+
+        public void Dispose()
+        {
+            Complete().Wait();
+        }
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Indexes/IndexReader.cs

@@ -0,0 +1,46 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using ZeroLevel.Sleopok.Engine.Models;
+using ZeroLevel.Sleopok.Engine.Services.Storage;
+
+namespace ZeroLevel.Sleopok.Engine.Services.Indexes
+{
+    internal sealed class IndexReader<T>
+        : IIndexReader<T>
+    {
+        private readonly DataStorage _storage;
+        private readonly IndexInfo<T> _indexInfo;
+        public IndexReader(DataStorage storage, IndexInfo<T> indexInfo)
+        {
+            _storage = storage;
+            _indexInfo = indexInfo;
+        }
+
+        public async Task<Dictionary<string, float>> Search(string[] tokens, bool exactMatch)
+        {
+            var documents = new Dictionary<string, float>();
+
+            foreach (var field in _indexInfo.Fields)
+            {
+                if (exactMatch && field.ExactMatch == false) 
+                    continue;
+                var docs = await _storage.GetDocuments(field.Name, tokens, field.Boost, exactMatch);
+                foreach (var doc in docs)
+                {
+                    if (doc.Value > 0.0001f)
+                    {
+                        if (documents.ContainsKey(doc.Key) == false)
+                        {
+                            documents[doc.Key] = doc.Value;
+                        }
+                        else
+                        {
+                            documents[doc.Key] += doc.Value;
+                        }
+                    }
+                }
+            }
+            return documents;
+        }
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Storage/DataStorage.cs

@@ -0,0 +1,171 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using ZeroLevel.Services.HashFunctions;
+using ZeroLevel.Services.PartitionStorage;
+
+namespace ZeroLevel.Sleopok.Engine.Services.Storage
+{
+    public sealed class DataStorage
+    {
+        private readonly IStore<string, string, byte[], StoreMetadata> _store;
+
+        private class DateSourceWriter :
+            IPartitionDataWriter
+        {
+            private readonly IStorePartitionBuilder<string, string, byte[]> _builder;
+            public DateSourceWriter(IStorePartitionBuilder<string, string, byte[]> builder)
+            {
+                _builder = builder;
+            }
+
+            public async Task Complete()
+            {
+                _builder.CompleteAdding();
+                _builder.Compress();
+                await _builder.RebuildIndex();
+                _builder.Dispose();
+            }
+
+            public async Task Write(string host, string document)
+            {
+                await _builder.Store(host, document);
+            }
+
+            public long GetTotalRecords() => _builder.TotalRecords;
+
+            public void Dispose()
+            {
+                _builder.Dispose();
+            }
+        }
+
+        public DataStorage(string rootFolder)
+        {
+            var serializers = new StoreSerializers<string, string, byte[]>(
+                async (w, n) => await w.WriteStringAsync(n),
+                async (w, n) => await w.WriteStringAsync(n),
+                async (w, n) => await w.WriteBytesAsync(n),
+
+                async (r) => { try { return new DeserializeResult<string>(true, await r.ReadStringAsync()); } catch { return new DeserializeResult<string>(false, string.Empty); } },
+                async (r) => { try { return new DeserializeResult<string>(true, await r.ReadStringAsync()); } catch { return new DeserializeResult<string>(false, string.Empty); } },
+                async (r) => { try { return new DeserializeResult<byte[]>(true, await r.ReadBytesAsync()); } catch { return new DeserializeResult<byte[]>(false, new byte[0]); } });
+
+            var options = new StoreOptions<string, string, byte[], StoreMetadata>
+            {
+                Index = new IndexOptions
+                {
+                    Enabled = true,
+                    StepType = IndexStepType.Step,
+                    StepValue = 32,
+                    EnableIndexInMemoryCachee = false
+                },
+                RootFolder = rootFolder,
+                FilePartition = new StoreFilePartition<string, StoreMetadata>("Token hash", (token, _) => Math.Abs(StringHash.DotNetFullHash(token) % 47).ToString()),
+                MergeFunction = list =>
+                {
+                    return Compressor.Compress(list.OrderBy(c => c).ToArray());
+                },
+                Partitions = new List<StoreCatalogPartition<StoreMetadata>>
+                {
+                    new StoreCatalogPartition<StoreMetadata>("Field", m => m.Field)
+                },
+                KeyComparer = (left, right) => string.Compare(left, right, true),
+                ThreadSafeWriting = true
+            };
+            _store = new Store<string, string, byte[], StoreMetadata>(options, serializers);
+        }
+
+        public IPartitionDataWriter GetWriter(string field)
+        {
+            return new DateSourceWriter(_store.CreateBuilder(new StoreMetadata { Field = field }));
+        }
+
+        private class PositionDocScore
+        {
+            private float score = 0.0f;
+            private int _last_position = -1;
+            private int count = 0;
+
+            public float GetScore(int total, bool exactMatch)
+            {
+                if (exactMatch)
+                {
+                    return (count == total) ? 1.0f : 0f;
+                }
+                return (score / (float)total) * count;
+            }
+
+            public void Increase(int position)
+            {
+                if (position == 0)
+                {
+                    score = 1.0f;
+                }
+                else
+                {
+                    var diff = position - _last_position;
+                    score += 1.0f / diff;
+                }
+                _last_position = position;
+                count++;
+            }
+        }
+
+        public async Task<Dictionary<string, float>> GetDocuments(string field, string[] tokens, float boost, bool exactMatch)
+        {
+            var documents = new Dictionary<string, PositionDocScore>();
+            var accessor = _store.CreateAccessor(new StoreMetadata { Field = field });
+            if (accessor != null)
+            {
+                using (accessor)
+                {
+                    int step = 0;
+                    foreach (var token in tokens)
+                    {
+                        var sr = await accessor.Find(token);
+                        if (sr.Success)
+                        {
+                            foreach (var doc in Compressor.DecompressToDocuments(sr.Value))
+                            {
+                                if (false == documents.ContainsKey(doc))
+                                {
+                                    documents.Add(doc, new PositionDocScore());
+                                }
+                                documents[doc].Increase(step);
+                            }
+                        }
+                    }
+                }
+            }
+            return documents.ToDictionary(d => d.Key, d => boost * d.Value.GetScore(tokens.Length, exactMatch));
+        }
+
+        public async Task Dump(string key, Stream stream)
+        {
+            using (TextWriter writer = new StreamWriter(stream))
+            {
+                await foreach (var i in _store.Bypass(new StoreMetadata { Field = key }))
+                {
+                    writer.WriteLine(i.Key);
+                    writer.WriteLine(string.Join(' ', Compressor.DecompressToDocuments(i.Value)));
+                }
+            }
+        }
+
+        public int HasData(string field)
+        {
+            var partition = _store.CreateAccessor(new StoreMetadata { Field = field });
+            if (partition != null)
+            {
+                using (partition)
+                {
+                    return partition.CountDataFiles();
+                }
+            }
+            return 0;
+        }
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Storage/IPartitionDataWriter.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Threading.Tasks;
+
+namespace ZeroLevel.Sleopok.Engine.Services.Storage
+{
+    public interface IPartitionDataWriter
+         : IDisposable
+    {
+        Task Write(string token, string document);
+        Task Complete();
+        long GetTotalRecords();
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Storage/StoreMetadata.cs

@@ -0,0 +1,13 @@
+namespace ZeroLevel.Sleopok.Engine.Services.Storage
+{
+    /// <summary>
+    /// Мета
+    /// </summary>
+    public sealed class StoreMetadata
+    {
+        /// <summary>
+        /// Поле документа
+        /// </summary>
+        public string Field { get; set; }
+    }
+}

ZeroLevel.Sleopok.Engine/Services/Storage/StoreRecord.cs

@@ -0,0 +1,14 @@
+namespace ZeroLevel.Sleopok.Engine.Services.Storage
+{
+    public sealed class StoreRecord
+    {
+        /// <summary>
+        /// Токен / ключ
+        /// </summary>
+        public string Token { get; set; }
+        /// <summary>
+        /// Идентификаторы документов / значение
+        /// </summary>
+        public string[] Documents { get; set; }
+    }
+}

ZeroLevel.Sleopok.Engine/SleoEngine.cs

@@ -0,0 +1,41 @@
+using System;
+using ZeroLevel.Sleopok.Engine.Models;
+using ZeroLevel.Sleopok.Engine.Services.Indexes;
+using ZeroLevel.Sleopok.Engine.Services.Storage;
+
+namespace ZeroLevel.Sleopok.Engine
+{
+    public class SleoEngine<T>
+    {
+        private readonly DataStorage _storage;
+        private readonly IndexInfo<T> _indexInfo;
+        public SleoEngine(string indexFolder, Func<T, string> identityExtractor)
+        {
+            _storage = new DataStorage(indexFolder);
+            _indexInfo = new IndexInfo<T>(identityExtractor);
+        }
+
+        public bool HasData()
+        {
+            var total = 0;
+            // healthy
+            foreach (var field in _indexInfo.Fields)
+            {
+                var count = _storage.HasData(field.Name);
+                Log.Debug($"Field: {field.Name}: {count} files");
+                total += count;
+            }
+            return total > 0;
+        }
+
+        public IIndexBuilder<T> CreateBuilder()
+        {
+            return new IndexBuilder<T>(_storage, _indexInfo);
+        }
+
+        public IIndexReader<T> CreateReader()
+        {
+            return new IndexReader<T>(_storage, _indexInfo);
+        }
+    }
+}

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

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.1</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ZeroLevel\ZeroLevel.csproj" />
+  </ItemGroup>
+
+</Project>

ZeroLevel.sln

@@ -3,14 +3,10 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.0.32014.148
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroLevel.Discovery", "ZeroLevel.Discovery\ZeroLevel.Discovery.csproj", "{5CE51CC9-7884-4E21-9D68-2321CA14312E}"
-EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "FileTransferTest", "FileTransferTest", "{FC074553-5D9F-4DF1-9130-7092E37DE768}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "TestPipeLine", "TestPipeLine", "{03ACF314-93FC-46FE-9FB8-3F46A01A5A15}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroLevel.Logger", "ZeroLevel.Logger\ZeroLevel.Logger.csproj", "{D1C061DB-3565-43C3-B8F3-628DE4908750}"
-EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "WPFExamples", "WPFExamples", "{7CCA0125-7A96-48FA-9F0D-BCF7EAD8FF9D}"
 	ProjectSection(SolutionItems) = preProject
 		WPFExamples\Controls\AlignableWrapPanel.cs = WPFExamples\Controls\AlignableWrapPanel.cs
@@ -27,8 +23,6 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "WPFExamples", "WPFExamples"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "ConnectionTest", "ConnectionTest", "{D5207A5A-2F27-4992-9BA5-0BDCFC59F133}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroNetworkMonitor", "ZeroNetworkMonitor\ZeroNetworkMonitor.csproj", "{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}"
-EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Tests", "Tests", "{380C828E-55D0-488B-A95F-4EFD20597BF5}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Consumer", "Tests\TestPipeLine\Consumer\Consumer.csproj", "{6C87E9EF-423F-47FC-BCFC-1A8E51336F02}"
@@ -53,11 +47,23 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TestApp", "Tests\TestApp\Te
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroLevel.UnitTests", "Tests\ZeroLevel.UnitTests\ZeroLevel.UnitTests.csproj", "{F73E2055-376A-4DC4-996E-E99009EC62D6}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ZeroLevel", "ZeroLevel\ZeroLevel.csproj", "{301D5818-59C5-4B46-9F80-A1054CC6CAA3}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroLevel", "ZeroLevel\ZeroLevel.csproj", "{301D5818-59C5-4B46-9F80-A1054CC6CAA3}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroLevel.MsSql", "ZeroLevel.MsSql\ZeroLevel.MsSql.csproj", "{3F9E6132-926C-46DE-B202-2355C126FD67}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroLevel.ML", "ZeroLevel.ML\ZeroLevel.ML.csproj", "{9F6690E5-D35D-4FA7-BDF0-FE320C4878E0}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Apps", "Apps", "{D60EF108-4E66-48A6-B3A9-59CF39C0D028}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroLevel.Discovery", "Apps\ZeroLevel.Discovery\ZeroLevel.Discovery.csproj", "{0DD8B913-013E-4531-BBDF-EB535FFBC218}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroLevel.Logger", "Apps\ZeroLevel.Logger\ZeroLevel.Logger.csproj", "{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ZeroNetworkMonitor", "Apps\ZeroNetworkMonitor\ZeroNetworkMonitor.csproj", "{D1506C69-4CA0-4D2C-8A07-3D786B449C68}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ZeroLevel.MsSql", "ZeroLevel.MsSql\ZeroLevel.MsSql.csproj", "{3F9E6132-926C-46DE-B202-2355C126FD67}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ZeroLevel.Sleopok.Engine", "ZeroLevel.Sleopok.Engine\ZeroLevel.Sleopok.Engine.csproj", "{469078A3-1CA9-46AD-BBBE-408A007FCEC8}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ZeroLevel.ML", "ZeroLevel.ML\ZeroLevel.ML.csproj", "{9F6690E5-D35D-4FA7-BDF0-FE320C4878E0}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sleopok.Tests", "Tests\Sleopok.Tests\Sleopok.Tests.csproj", "{4F5251A0-6639-40B0-91A7-6A1F39DF823E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -69,42 +75,6 @@ Global
 		Release|x86 = Release|x86
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Debug|x64.ActiveCfg = Debug|x64
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Debug|x64.Build.0 = Debug|x64
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Debug|x86.ActiveCfg = Debug|x86
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Debug|x86.Build.0 = Debug|x86
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Release|x64.ActiveCfg = Release|x64
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Release|x64.Build.0 = Release|x64
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Release|x86.ActiveCfg = Release|x86
-		{5CE51CC9-7884-4E21-9D68-2321CA14312E}.Release|x86.Build.0 = Release|x86
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Debug|x64.ActiveCfg = Debug|x64
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Debug|x64.Build.0 = Debug|x64
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Debug|x86.ActiveCfg = Debug|x86
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Debug|x86.Build.0 = Debug|x86
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Release|Any CPU.Build.0 = Release|Any CPU
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Release|x64.ActiveCfg = Release|x64
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Release|x64.Build.0 = Release|x64
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Release|x86.ActiveCfg = Release|x86
-		{D1C061DB-3565-43C3-B8F3-628DE4908750}.Release|x86.Build.0 = Release|x86
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Debug|x64.ActiveCfg = Debug|x64
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Debug|x64.Build.0 = Debug|x64
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Debug|x86.Build.0 = Debug|Any CPU
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Release|Any CPU.Build.0 = Release|Any CPU
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Release|x64.ActiveCfg = Release|x64
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Release|x64.Build.0 = Release|x64
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Release|x86.ActiveCfg = Release|Any CPU
-		{B89249F8-BD37-4AF7-9BB5-65855FA3B3FA}.Release|x86.Build.0 = Release|Any CPU
 		{6C87E9EF-423F-47FC-BCFC-1A8E51336F02}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{6C87E9EF-423F-47FC-BCFC-1A8E51336F02}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{6C87E9EF-423F-47FC-BCFC-1A8E51336F02}.Debug|x64.ActiveCfg = Debug|x64
@@ -273,6 +243,66 @@ Global
 		{9F6690E5-D35D-4FA7-BDF0-FE320C4878E0}.Release|x64.Build.0 = Release|Any CPU
 		{9F6690E5-D35D-4FA7-BDF0-FE320C4878E0}.Release|x86.ActiveCfg = Release|Any CPU
 		{9F6690E5-D35D-4FA7-BDF0-FE320C4878E0}.Release|x86.Build.0 = Release|Any CPU
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Debug|x64.ActiveCfg = Debug|x64
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Debug|x64.Build.0 = Debug|x64
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Debug|x86.ActiveCfg = Debug|x86
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Debug|x86.Build.0 = Debug|x86
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Release|x64.ActiveCfg = Release|x64
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Release|x64.Build.0 = Release|x64
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Release|x86.ActiveCfg = Release|x86
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218}.Release|x86.Build.0 = Release|x86
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Debug|x64.ActiveCfg = Debug|x64
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Debug|x64.Build.0 = Debug|x64
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Debug|x86.ActiveCfg = Debug|x86
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Debug|x86.Build.0 = Debug|x86
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Release|Any CPU.Build.0 = Release|Any CPU
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Release|x64.ActiveCfg = Release|x64
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Release|x64.Build.0 = Release|x64
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Release|x86.ActiveCfg = Release|x86
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6}.Release|x86.Build.0 = Release|x86
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Debug|x64.ActiveCfg = Debug|x64
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Debug|x64.Build.0 = Debug|x64
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Debug|x86.Build.0 = Debug|Any CPU
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Release|x64.ActiveCfg = Release|x64
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Release|x64.Build.0 = Release|x64
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Release|x86.ActiveCfg = Release|Any CPU
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68}.Release|x86.Build.0 = Release|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Debug|x64.Build.0 = Debug|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Debug|x86.Build.0 = Debug|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Release|x64.ActiveCfg = Release|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Release|x64.Build.0 = Release|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Release|x86.ActiveCfg = Release|Any CPU
+		{469078A3-1CA9-46AD-BBBE-408A007FCEC8}.Release|x86.Build.0 = Release|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Debug|x64.Build.0 = Debug|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Debug|x86.Build.0 = Debug|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Release|x64.ActiveCfg = Release|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Release|x64.Build.0 = Release|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Release|x86.ActiveCfg = Release|Any CPU
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -292,6 +322,10 @@ Global
 		{9525DFC1-91F4-4B38-BDD0-7C46507C636F} = {380C828E-55D0-488B-A95F-4EFD20597BF5}
 		{3C6C5D02-93B7-4842-97C0-870B4B6AF5F5} = {380C828E-55D0-488B-A95F-4EFD20597BF5}
 		{F73E2055-376A-4DC4-996E-E99009EC62D6} = {380C828E-55D0-488B-A95F-4EFD20597BF5}
+		{0DD8B913-013E-4531-BBDF-EB535FFBC218} = {D60EF108-4E66-48A6-B3A9-59CF39C0D028}
+		{F7464B5D-B66A-412C-8ED3-346A1AC9CBE6} = {D60EF108-4E66-48A6-B3A9-59CF39C0D028}
+		{D1506C69-4CA0-4D2C-8A07-3D786B449C68} = {D60EF108-4E66-48A6-B3A9-59CF39C0D028}
+		{4F5251A0-6639-40B0-91A7-6A1F39DF823E} = {380C828E-55D0-488B-A95F-4EFD20597BF5}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {A65DB16F-877D-4586-A9F3-8BBBFBAF5CEB}

ZeroLevel/Models/BaseModel.cs

@@ -11,9 +11,9 @@ namespace ZeroLevel.Models
 
         public bool Equals(BaseModel other)
         {
-            if (this == null)
+            if (this == null!)
                 throw new NullReferenceException();
-            if (other == null)
+            if (other == null!)
                 return false;
             if (ReferenceEquals(this, other))
                 return true;
@@ -24,10 +24,10 @@ namespace ZeroLevel.Models
 
         public override bool Equals(object obj)
         {
-            if (this == null)
+            if (this == null!)
                 throw new NullReferenceException();
 
-            return Equals(obj as BaseModel);
+            return Equals((obj as BaseModel)!);
         }
 
         public static bool operator ==(BaseModel first, BaseModel second) => Equals(first, second);

ZeroLevel/Services/BaseZeroService.cs

@@ -72,30 +72,30 @@ namespace ZeroLevel.Services.Applications
                 this.Type = ReadServiceType(set);
         }
 
-        private string ReadName(IConfigurationSet set = null)
+        private string ReadName(IConfigurationSet set = null!)
         {
             return FindInConfig<string>(set, new[] { "ServiceName", "AppName" }, string.Empty, "service")
                 ?? this.GetType().Name;
         }
 
-        private string ReadKey(IConfigurationSet set = null)
+        private string ReadKey(IConfigurationSet set = null!)
         {
             return FindInConfig<string>(set, new[] { "ServiceKey", "AppKey" }, string.Empty, "service");
         }
 
-        private string ReadVersion(IConfigurationSet set = null)
+        private string ReadVersion(IConfigurationSet set = null!)
         {
             return FindInConfig<string>(set, new[] { "Version", "AppVersion" }, string.Empty, "service")
                 ?? "1.0";
         }
 
-        private string ReadServiceGroup(IConfigurationSet set = null)
+        private string ReadServiceGroup(IConfigurationSet set = null!)
         {
             return FindInConfig<string>(set, new[] { "DiscoveryGroup", "ServiceGroup" }, string.Empty, "service")
                 ?? DEFAULT_GROUP_NAME;
         }
 
-        private string ReadServiceType(IConfigurationSet set = null)
+        private string ReadServiceType(IConfigurationSet set = null!)
         {
             return FindInConfig<string>(set, new[] { "DiscoveryType", "ServiceType" }, string.Empty, "service")
                 ?? DEFAULT_TYPE_NAME;
@@ -299,13 +299,13 @@ namespace ZeroLevel.Services.Applications
                             if (args.Length == 1)
                             {
                                 var handler = CreateDelegate(typeof(MessageHandler), mi, this);
-                                register_message_handler.Invoke(server, new object[] { (attr as ExchangeHandlerAttribute).Inbox, handler });
+                                register_message_handler.Invoke(server, new object[] { (attr as ExchangeHandlerAttribute)!.Inbox, handler });
                             }
                             else
                             {
                                 var handler = CreateDelegate(typeof(MessageHandler<>).MakeGenericType(args[1].ParameterType), mi, this);
                                 MethodInfo genericMethod = register_message_handler_with_msg.MakeGenericMethod(args[1].ParameterType);
-                                genericMethod.Invoke(server, new object[] { (attr as ExchangeHandlerAttribute).Inbox, handler });
+                                genericMethod.Invoke(server, new object[] { (attr as ExchangeHandlerAttribute)!.Inbox, handler });
                             }
                         }
 
@@ -323,7 +323,7 @@ namespace ZeroLevel.Services.Applications
                             var genArgType = args[1].ParameterType;
                             MethodInfo genericMethod = register_request_handler.MakeGenericMethod(genArgType, returnType);
                             var requestHandler = CreateDelegate(typeof(RequestHandler<,>).MakeGenericType(args[1].ParameterType, returnType), mi, this);
-                            genericMethod.Invoke(server, new object[] { (attr as ExchangeReplierAttribute).Inbox, requestHandler });
+                            genericMethod.Invoke(server, new object[] { (attr as ExchangeReplierAttribute)!.Inbox, requestHandler });
                         }
 
                         else if (attr.GetType() == typeof(ExchangeMainReplierWithoutArgAttribute))
@@ -338,7 +338,7 @@ namespace ZeroLevel.Services.Applications
                             var returnType = mi.ReturnType;
                             MethodInfo genericMethod = register_request_handler_without_msg.MakeGenericMethod(returnType);
                             var requestHandler = CreateDelegate(typeof(RequestHandler<>).MakeGenericType(returnType), mi, this);
-                            genericMethod.Invoke(server, new object[] { (attr as ExchangeReplierWithoutArgAttribute).Inbox, requestHandler });
+                            genericMethod.Invoke(server, new object[] { (attr as ExchangeReplierWithoutArgAttribute)!.Inbox, requestHandler });
                         }
                     }
                 }

ZeroLevel/Services/Bootstrap.cs

@@ -127,32 +127,32 @@ namespace ZeroLevel
         }
 
         public static BootstrapFluent Startup<T>(string[] args,
-            Func<bool> preStartConfiguration = null,
-            Func<bool> postStartConfiguration = null)
+            Func<bool> preStartConfiguration = null!,
+            Func<bool> postStartConfiguration = null!)
             where T : IZeroService
         {
-            var service = Initialize<T>(args, null,
+            var service = Initialize<T>(args, null!,
                 preStartConfiguration, postStartConfiguration);
             return new BootstrapFluent(service);
         }
 
         public static BootstrapFluent Startup<T>(string[] args,
             Func<IConfigurationSet> configuration,
-            Func<bool> preStartConfiguration = null,
-            Func<bool> postStartConfiguration = null)
+            Func<bool> preStartConfiguration = null!,
+            Func<bool> postStartConfiguration = null!)
             where T : IZeroService
         {
-            var service = Initialize<T>(args, configuration?.Invoke(), preStartConfiguration, postStartConfiguration);
+            var service = Initialize<T>(args, configuration?.Invoke()!, preStartConfiguration, postStartConfiguration);
             return new BootstrapFluent(service);
         }
 
         private static IZeroService Initialize<T>(string[] args,
             IConfigurationSet configurationSet,
-            Func<bool> preStartConfiguration = null,
-            Func<bool> postStartConfiguration = null)
+            Func<bool> preStartConfiguration = null!,
+            Func<bool> postStartConfiguration = null!)
             where T : IZeroService
         {
-            IZeroService service = null;
+            IZeroService service = null!;
             IConfigurationSet config = Configuration.DefaultSet;
             config.CreateSection("commandline", Configuration.ReadFromCommandLine(args));
             if (configurationSet != null)
@@ -168,13 +168,13 @@ namespace ZeroLevel
                     if (preStartConfiguration() == false)
                     {
                         Log.SystemInfo("[Bootstrap] Service start canceled, because custom preconfig return false");
-                        return null;
+                        return null!;
                     }
                 }
                 catch (Exception ex)
                 {
                     Log.SystemError(ex, "[Bootstrap] Service start canceled, preconfig faulted");
-                    return null;
+                    return null!;
                 }
             }
             try
@@ -204,7 +204,7 @@ namespace ZeroLevel
             return service;
         }
 
-        public static IExchange CreateExchange() => new Exchange(null);
+        public static IExchange CreateExchange() => new Exchange(null!);
 
         public static void Shutdown()
         {

ZeroLevel/Services/Collections/ConcurrentHashSet.cs

@@ -116,7 +116,7 @@ namespace ZeroLevel.Collections
         /// uses the default comparer for the item type.
         /// </summary>
         public ConcurrentHashSet()
-            : this(DefaultConcurrencyLevel, DefaultCapacity, true, null)
+            : this(DefaultConcurrencyLevel, DefaultCapacity, true, null!)
         {
         }
 
@@ -136,7 +136,7 @@ namespace ZeroLevel.Collections
         /// <exception cref="ArgumentOutOfRangeException"> <paramref name="capacity"/> is less than
         /// 0.</exception>
         public ConcurrentHashSet(int concurrencyLevel, int capacity)
-            : this(concurrencyLevel, capacity, false, null)
+            : this(concurrencyLevel, capacity, false, null!)
         {
         }
 
@@ -152,7 +152,7 @@ namespace ZeroLevel.Collections
         /// <see cref="ConcurrentHashSet{T}"/>.</param>
         /// <exception cref="ArgumentNullException"><paramref name="collection"/> is a null reference.</exception>
         public ConcurrentHashSet(IEnumerable<T> collection)
-            : this(collection, null)
+            : this(collection, null!)
         {
         }
 
@@ -375,7 +375,7 @@ namespace ZeroLevel.Collections
                         continue;
                     }
 
-                    Node previous = null;
+                    Node previous = null!;
                     for (var current = tables.Buckets[bucketNo]; current != null; current = current.Next)
                     {
                         Debug.Assert((previous == null && current == tables.Buckets[bucketNo]) || previous!.Next == current);
@@ -455,8 +455,8 @@ namespace ZeroLevel.Collections
             public Enumerator(ConcurrentHashSet<T> set)
             {
                 _set = set;
-                _buckets = null;
-                _node = null;
+                _buckets = null!;
+                _node = null!;
                 Current = default!;
                 _i = -1;
                 _state = StateUninitialized;
@@ -468,15 +468,15 @@ namespace ZeroLevel.Collections
             /// <value>The element in the collection at the current position of the enumerator.</value>
             public T Current { get; private set; }
 
-            object IEnumerator.Current => Current;
+            object IEnumerator.Current => Current!;
 
             /// <summary>
             /// Sets the enumerator to its initial position, which is before the first element in the collection.
             /// </summary>
             public void Reset()
             {
-                _buckets = null;
-                _node = null;
+                _buckets = null!;
+                _node = null!;
                 Current = default!;
                 _i = -1;
                 _state = StateUninitialized;

ZeroLevel/Services/Collections/FixSizeQueue.cs

@@ -46,13 +46,13 @@ namespace ZeroLevel.Services.Collections
         public bool Equals(T x, T y)
         {
             if (x == null && y == null) return true;
-            if ((object)x == (object)y) return true;
             if (x == null || y == null) return false;
+            if ((object)x == (object)y) return true;
             if (ReferenceEquals(x, y)) return true;
             return x.Equals(y);
         }
 
-        public bool Contains(T item, IComparer<T> comparer = null)
+        public bool Contains(T item, IComparer<T> comparer = null!)
         {
             lock (_accessLocker)
             {

ZeroLevel/Services/Config/BaseConfiguration.cs

@@ -527,8 +527,8 @@ namespace ZeroLevel.Services.Config
                         else
                         {
                             var elements = values.Select(v => parser.Parse(v)).ToArray();
-                            var arrayBuilder = CollectionFactory.CreateArray(itemType, (elements[0] as Array).Length);
-                            foreach (var item in (elements[0] as Array))
+                            var arrayBuilder = CollectionFactory.CreateArray(itemType, (elements[0] as Array)?.Length ?? 0);
+                            foreach (var item in (elements[0] as Array) ?? Array.Empty<object>())
                             {
                                 arrayBuilder.Set(item, index);
                                 index++;

ZeroLevel/Services/Config/Implementation/AppWebConfigReader.cs

@@ -12,7 +12,7 @@ namespace ZeroLevel.Services.Config.Implementation
 
         public bool ExistsAppConfigFile => string.IsNullOrWhiteSpace(_configFilePath) == false;
 
-        internal AppWebConfigReader(string configFilePath = null)
+        internal AppWebConfigReader(string configFilePath = null!)
         {
             if (configFilePath == null)
             {
@@ -69,14 +69,16 @@ namespace ZeroLevel.Services.Config.Implementation
                     SelectMany(x => x.Nodes().Where(n => null != (n as XElement)).Select(n =>
                     {
                         var xe = n as XElement;
-                        return new Tuple<string, string>(FindName(xe), FindValue(xe));
-                    }));
+                        return new Tuple<string, string>(FindName(xe!), FindValue(xe!));
+                    }))
+                    .Where(t => string.IsNullOrWhiteSpace(t.Item1) == false);
             }
             return Enumerable.Empty<Tuple<string, string>>();
         }
 
         private static string FindName(XElement n)
         {
+            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" })
@@ -89,6 +91,7 @@ namespace ZeroLevel.Services.Config.Implementation
 
         private static string FindValue(XElement n)
         {
+            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/EnvironmentVariablesConfigReader.cs

@@ -12,7 +12,7 @@ namespace ZeroLevel.Services.Config.Implementation
             while (enumerator.MoveNext())
             {
                 string key = (string)enumerator.Entry.Key;
-                string value = ((string)enumerator.Entry.Value) ?? string.Empty;
+                string value = (enumerator.Entry.Value as string) ?? string.Empty;
                 result.Append(key, value);
             }
             return result;
@@ -23,4 +23,4 @@ namespace ZeroLevel.Services.Config.Implementation
             return Configuration.CreateSet(ReadConfiguration());
         }
     }
-}
+}

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

@@ -68,54 +68,54 @@ namespace DOM.DSL.Model
 
         public void Bootstrap()
         {
-            if (null == SectionPrefix) SectionPrefix = null;
-            if (null == SectionPostfix) SectionPostfix = null;
-            if (null == ParagraphPrefix) ParagraphPrefix = null;
-            if (null == ParagraphPostfix) ParagraphPostfix = null;
-            if (null == ListPrefix) ListPrefix = null;
-            if (null == ListPostfix) ListPostfix = null;
-            if (null == ListItemPrefix) ListItemPrefix = null;
-            if (null == ListItemPostfix) ListItemPostfix = null;
-            if (null == TablePrefix) TablePrefix = null;
-            if (null == TablePostfix) TablePostfix = null;
-            if (null == ColumnsPrefix) ColumnsPrefix = null;
-            if (null == ColumnsPostfix) ColumnsPostfix = null;
-            if (null == ColumnPrefix) ColumnPrefix = null;
-            if (null == ColumnTemplate) ColumnTemplate = null;
-            if (null == ColumnPostfix) ColumnPostfix = null;
-            if (null == RowPrefix) RowPrefix = null;
-            if (null == RowPostfix) RowPostfix = null;
-            if (null == CellPrefix) CellPrefix = null;
-            if (null == CellPostfix) CellPostfix = null;
-            if (null == FirstRowCellPrefix) FirstRowCellPrefix = null;
-            if (null == FirstRowCellPostfix) FirstRowCellPostfix = null;
-            if (null == AudioplayerPrefix) AudioplayerPrefix = null;
-            if (null == AudioplayerPostfix) AudioplayerPostfix = null;
-            if (null == VideoplayerPrefix) VideoplayerPrefix = null;
-            if (null == VideoplayerPostfix) VideoplayerPostfix = null;
-            if (null == GalleryPrefix) GalleryPrefix = null;
-            if (null == GalleryPostfix) GalleryPostfix = null;
-            if (null == FormPrefix) FormPrefix = null;
-            if (null == FormTemplate) FormTemplate = null;
-            if (null == FormPostfix) FormPostfix = null;
-            if (null == VideoPrefix) VideoPrefix = null;
-            if (null == VideoTemplate) VideoTemplate = null;
-            if (null == VideoPostfix) VideoPostfix = null;
-            if (null == AudioPrefix) AudioPrefix = null;
-            if (null == AudioTemplate) AudioTemplate = null;
-            if (null == AudioPostfix) AudioPostfix = null;
-            if (null == ImagePrefix) ImagePrefix = null;
-            if (null == ImageTemplate) ImageTemplate = null;
-            if (null == ImagePostfix) ImagePostfix = null;
-            if (null == LinkPrefix) LinkPrefix = null;
-            if (null == LinkTemplate) LinkTemplate = null;
-            if (null == LinkPostfix) LinkPostfix = null;
-            if (null == QuotePrefix) QuotePrefix = null;
+            if (null == SectionPrefix) SectionPrefix = null!;
+            if (null == SectionPostfix) SectionPostfix = null!;
+            if (null == ParagraphPrefix) ParagraphPrefix = null!;
+            if (null == ParagraphPostfix) ParagraphPostfix = null!;
+            if (null == ListPrefix) ListPrefix = null!;
+            if (null == ListPostfix) ListPostfix = null!;
+            if (null == ListItemPrefix) ListItemPrefix = null!;
+            if (null == ListItemPostfix) ListItemPostfix = null!;
+            if (null == TablePrefix) TablePrefix = null!;
+            if (null == TablePostfix) TablePostfix = null!;
+            if (null == ColumnsPrefix) ColumnsPrefix = null!;
+            if (null == ColumnsPostfix) ColumnsPostfix = null!;
+            if (null == ColumnPrefix) ColumnPrefix = null!;
+            if (null == ColumnTemplate) ColumnTemplate = null!;
+            if (null == ColumnPostfix) ColumnPostfix = null!;
+            if (null == RowPrefix) RowPrefix = null!;
+            if (null == RowPostfix) RowPostfix = null!;
+            if (null == CellPrefix) CellPrefix = null!;
+            if (null == CellPostfix) CellPostfix = null!;
+            if (null == FirstRowCellPrefix) FirstRowCellPrefix = null!;
+            if (null == FirstRowCellPostfix) FirstRowCellPostfix = null!;
+            if (null == AudioplayerPrefix) AudioplayerPrefix = null!;
+            if (null == AudioplayerPostfix) AudioplayerPostfix = null!;
+            if (null == VideoplayerPrefix) VideoplayerPrefix = null!;
+            if (null == VideoplayerPostfix) VideoplayerPostfix = null!;
+            if (null == GalleryPrefix) GalleryPrefix = null!;
+            if (null == GalleryPostfix) GalleryPostfix = null!;
+            if (null == FormPrefix) FormPrefix = null!;
+            if (null == FormTemplate) FormTemplate = null!;
+            if (null == FormPostfix) FormPostfix = null!;
+            if (null == VideoPrefix) VideoPrefix = null!;
+            if (null == VideoTemplate) VideoTemplate = null!;
+            if (null == VideoPostfix) VideoPostfix = null!;
+            if (null == AudioPrefix) AudioPrefix = null!;
+            if (null == AudioTemplate) AudioTemplate = null!;
+            if (null == AudioPostfix) AudioPostfix = null!;
+            if (null == ImagePrefix) ImagePrefix = null!;
+            if (null == ImageTemplate) ImageTemplate = null!;
+            if (null == ImagePostfix) ImagePostfix = null!;
+            if (null == LinkPrefix) LinkPrefix = null!;
+            if (null == LinkTemplate) LinkTemplate = null!;
+            if (null == LinkPostfix) LinkPostfix = null!;
+            if (null == QuotePrefix) QuotePrefix = null!;
             if (null == QuoteTemplate) QuoteTemplate = new TBlockToken(new[] { new TElementToken { ElementName = "self" } });
-            if (null == QuotePostfix) QuotePostfix = null;
-            if (null == TextPrefix) TextPrefix = null;
+            if (null == QuotePostfix) QuotePostfix = null!;
+            if (null == TextPrefix) TextPrefix = null!;
             if (null == TextTemplate) TextTemplate = new TBlockToken(new[] { new TElementToken { ElementName = "self" } });
-            if (null == TextPostfix) TextPostfix = null;
+            if (null == TextPostfix) TextPostfix = null!;
         }
 
         public void UpdateRule(string elementName, string functionName, TBlockToken rule_token, string special)
@@ -134,7 +134,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            ListPostfix = ListPrefix = null;
+                            ListPostfix = ListPrefix = null!;
                             break;
                     }
                     break;
@@ -151,7 +151,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            ListItemPrefix = ListItemPostfix = null;
+                            ListItemPrefix = ListItemPostfix = null!;
                             break;
                     }
                     break;
@@ -172,7 +172,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            TextPrefix = TextTemplate = TextPostfix = null;
+                            TextPrefix = TextTemplate = TextPostfix = null!;
                             break;
                     }
                     break;
@@ -193,7 +193,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            LinkPrefix = LinkTemplate = LinkPostfix = null;
+                            LinkPrefix = LinkTemplate = LinkPostfix = null!;
                             break;
                     }
                     break;
@@ -214,7 +214,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            ImagePrefix = ImageTemplate = ImagePostfix = null;
+                            ImagePrefix = ImageTemplate = ImagePostfix = null!;
                             break;
                     }
                     break;
@@ -235,7 +235,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            QuotePrefix = QuoteTemplate = QuotePostfix = null;
+                            QuotePrefix = QuoteTemplate = QuotePostfix = null!;
                             break;
                     }
                     break;
@@ -256,7 +256,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            FormPrefix = FormTemplate = FormPostfix = null;
+                            FormPrefix = FormTemplate = FormPostfix = null!;
                             break;
                     }
                     break;
@@ -277,7 +277,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            VideoPrefix = VideoTemplate = VideoPostfix = null;
+                            VideoPrefix = VideoTemplate = VideoPostfix = null!;
                             break;
                     }
                     break;
@@ -298,7 +298,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            AudioPrefix = AudioTemplate = AudioPostfix = null;
+                            AudioPrefix = AudioTemplate = AudioPostfix = null!;
                             break;
                     }
                     break;
@@ -315,7 +315,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            SectionPrefix = SectionPostfix = null;
+                            SectionPrefix = SectionPostfix = null!;
                             break;
                     }
                     break;
@@ -332,7 +332,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            ParagraphPrefix = ParagraphPostfix = null;
+                            ParagraphPrefix = ParagraphPostfix = null!;
                             break;
                     }
                     break;
@@ -349,15 +349,15 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            TablePrefix = TablePostfix = null;
+                            TablePrefix = TablePostfix = null!;
                             break;
 
                         case "special": // Using a hardcoded table conversion
                                         //TablePrefix = TablePostfix = null;
-                            ColumnsPrefix = ColumnsPostfix = null;
-                            ColumnPrefix = ColumnTemplate = ColumnPostfix = null;
-                            RowPrefix = RowPostfix = null;
-                            CellPrefix = CellPostfix = null;
+                            ColumnsPrefix = ColumnsPostfix = null!;
+                            ColumnPrefix = ColumnTemplate = ColumnPostfix = null!;
+                            RowPrefix = RowPostfix = null!;
+                            CellPrefix = CellPostfix = null!;
                             // Args: (style, paddings l-t-r-b, maxcellwidth, maxtablewidth)
                             UseSpecialTableBuilder = true;
                             SpecialTableBuilder = SpecialTableBuilderFactory.CreateSpecialTableBuilder(special);
@@ -378,7 +378,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            ColumnsPrefix = ColumnsPostfix = null;
+                            ColumnsPrefix = ColumnsPostfix = null!;
                             break;
                     }
                     break;
@@ -399,7 +399,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            ColumnPrefix = ColumnTemplate = ColumnPostfix = null;
+                            ColumnPrefix = ColumnTemplate = ColumnPostfix = null!;
                             break;
                     }
                     break;
@@ -416,7 +416,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            RowPrefix = RowPostfix = null;
+                            RowPrefix = RowPostfix = null!;
                             break;
                     }
                     break;
@@ -433,7 +433,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            CellPrefix = CellPostfix = null;
+                            CellPrefix = CellPostfix = null!;
                             break;
                     }
                     break;
@@ -450,7 +450,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            VideoplayerPrefix = VideoplayerPostfix = null;
+                            VideoplayerPrefix = VideoplayerPostfix = null!;
                             break;
                     }
                     break;
@@ -467,7 +467,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            AudioplayerPrefix = AudioplayerPostfix = null;
+                            AudioplayerPrefix = AudioplayerPostfix = null!;
                             break;
                     }
                     break;
@@ -484,7 +484,7 @@ namespace DOM.DSL.Model
                             break;
 
                         case "ignore":
-                            GalleryPrefix = GalleryPostfix = null;
+                            GalleryPrefix = GalleryPostfix = null!;
                             break;
                     }
                     break;

ZeroLevel/Services/DOM/DSL/Services/SpecialTableBuilderFactory.cs

@@ -9,8 +9,8 @@ namespace DOM.DSL.Services
     {
         public static ISpecialTableBuilder CreateSpecialTableBuilder(string command)
         {
-            if (string.IsNullOrWhiteSpace(command)) return null;
-            ISpecialTableBuilder result = null;
+            if (string.IsNullOrWhiteSpace(command)) return null!;
+            ISpecialTableBuilder result = null!;
             var args = command.Split(',').Select(s => s.Trim()).ToArray();
             switch (args[0])
             {

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

@@ -63,7 +63,7 @@ namespace DOM.DSL.Services
                         foreach (var i in _list) list.Add(i.ToString());
                         _elementType = typeof(string);
                         _list.Clear();
-                        _list = null;
+                        _list = null!;
                         _list = list;
                         list.Add(item.ToString());
                     }
@@ -72,7 +72,7 @@ namespace DOM.DSL.Services
 
             public object First()
             {
-                return (_list.Count > 0) ? _list[0] : null;
+                return (_list.Count > 0) ? _list[0] : null!;
             }
 
             public IList Complete()
@@ -907,7 +907,7 @@ namespace DOM.DSL.Services
 
         private void SelectProperty(TagMetadata tags, string property, string propertyIndex)
         {
-            IList enumerable = null;
+            IList enumerable = null!;
             switch (property.Trim().ToLowerInvariant())
             {
                 case "places":
@@ -1322,7 +1322,7 @@ namespace DOM.DSL.Services
                 {
                     if (headers.Count == 0)
                     {
-                        Reset(null);
+                        Reset(null!);
                     }
                     else if (headers.Count == 1)
                     {
@@ -1390,7 +1390,7 @@ namespace DOM.DSL.Services
         {
             if (_current == null)
             {
-                args = null;
+                args = null!;
                 return;
             }
             //args = args_getter(this);
@@ -1418,7 +1418,7 @@ namespace DOM.DSL.Services
                                 var container = _factory.Get(i);
                                 if (args.Length > 1)
                                 {
-                                    container.MoveToProperty(args[1].ToString(), null);
+                                    container.MoveToProperty(args[1].ToString(), null!);
                                 }
                                 if (result.Length > 0) result.Append(separator);
                                 result.Append(container.ToString());
@@ -1439,7 +1439,7 @@ namespace DOM.DSL.Services
                     {
                         var format = (args != null && args.Length > 0) ? args[0].ToString() : null;
                         var culture = (args != null && args.Length > 1) ? args[1].ToString() : null;
-                        Reset(FormattedDateTime((DateTime)_current, format, culture));
+                        Reset(FormattedDateTime((DateTime)_current, format!, culture!));
                     }
                     break;
 
@@ -1792,16 +1792,16 @@ namespace DOM.DSL.Services
                         var key = args[0].ToString();
                         if (_render.BufferDictionary.ContainsKey(key) == false)
                         {
-                            _render.BufferDictionary.Add(key, this._current);
+                            _render.BufferDictionary.Add(key, this._current!);
                         }
                         else
                         {
-                            _render.BufferDictionary[key] = this._current;
+                            _render.BufferDictionary[key] = this._current!;
                         }
-                        Reset(null);
+                        Reset(null!);
                     }
                 }
-                args = null;
+                args = null!;
                 return;
             }
             if (function.Equals("where", StringComparison.OrdinalIgnoreCase))
@@ -1923,7 +1923,7 @@ namespace DOM.DSL.Services
                                     }
                                     else
                                     {
-                                        Reset(null);
+                                        Reset(null!);
                                     }
                                 }
                                 else if (_current is string)
@@ -1935,7 +1935,7 @@ namespace DOM.DSL.Services
                                     }
                                     else
                                     {
-                                        Reset(null);
+                                        Reset(null!);
                                     }
                                 }
                                 else if (_current is IEnumerable)
@@ -1950,7 +1950,7 @@ namespace DOM.DSL.Services
                                         }
                                         _i++;
                                     }
-                                    if (found == false) Reset(null);
+                                    if (found == false) Reset(null!);
                                 }
                             }
                         }
@@ -1969,7 +1969,7 @@ namespace DOM.DSL.Services
                                     {
                                         if (i == null) continue;
                                         var container = _factory.Get(i);
-                                        container.MoveToProperty(property, property_index);
+                                        container.MoveToProperty(property, property_index!);
                                         list.Append(container.Current);
                                         _factory.Release(container);
                                     }
@@ -1978,7 +1978,7 @@ namespace DOM.DSL.Services
                                 else
                                 {
                                     var container = _factory.Get(_current);
-                                    container.MoveToProperty(property, property_index);
+                                    container.MoveToProperty(property, property_index!);
                                     Reset(container.Current);
                                     _factory.Release(container);
                                 }
@@ -2081,10 +2081,15 @@ namespace DOM.DSL.Services
                         if (_current is List<TContainer>)
                         {
                             var list = _current as List<TContainer>;
+                            if (list == null)
+                            {
+                                _current = new List<TContainer>();
+                                list = _current as List<TContainer>;
+                            }
                             foreach (var i in args)
-                                list.Add(i);
-                            Reset(list);
-                            args = null;
+                                list!.Add(i);
+                            Reset(list!);
+                            args = null!;
                         }
                         break;
                 }
@@ -2491,10 +2496,10 @@ namespace DOM.DSL.Services
 
         #region Conditions
 
-        public bool Any(TContainer[] set = null, bool ignoreCase = true)
+        public bool Any(TContainer[] set = null!, bool ignoreCase = true)
         {
             if (_current == null) return false;
-            if (set.Any())
+            if (set?.Any() ?? false)
             {
                 if (_current is IEnumerable && false == (_current is string))
                 {
@@ -2524,7 +2529,7 @@ namespace DOM.DSL.Services
             if (set == null || set?.Length == 0) return false;
             if (_current is IEnumerable && false == (_current is string))
             {
-                foreach (var t in set)
+                foreach (var t in set!)
                 {
                     bool contains = false;
                     foreach (var c in (IEnumerable)_current)
@@ -2541,7 +2546,7 @@ namespace DOM.DSL.Services
             else if (_current is string)
             {
                 var line = (string)_current;
-                foreach (var t in set)
+                foreach (var t in set!)
                 {
                     if (line.IndexOf(t.ToString(), StringComparison.OrdinalIgnoreCase) == -1) return false;
                 }
@@ -2549,7 +2554,7 @@ namespace DOM.DSL.Services
             }
             else
             {
-                foreach (var t in set)
+                foreach (var t in set!)
                 {
                     if (CompareWith(t, ignoreCase) != 0) return false;
                 }
@@ -2726,7 +2731,7 @@ namespace DOM.DSL.Services
 
         private const string DEFAULT_DATETIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
 
-        private static string FormattedDateTime(DateTime dt, string format = null, string culture = null)
+        private static string FormattedDateTime(DateTime dt, string format = null!, string culture = null!)
         {
             CultureInfo ci;
             if (culture != null)

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

@@ -57,7 +57,7 @@ namespace DOM.DSL.Services
             Factory = new TContainerFactory(this);
         }
 
-        public void Resolve(TToken token, Action<TContainer> handler, bool release = true, TContainer self = null)
+        public void Resolve(TToken token, Action<TContainer> handler, bool release = true, TContainer self = null!)
         {
             var self_copy = self == null ? null : Factory.Get(self.Current, self.Index);
             try
@@ -70,7 +70,7 @@ namespace DOM.DSL.Services
                 }
                 else if (token is TElementToken)
                 {
-                    var containers = ResolveElementToken(token.AsElementToken(), self_copy);
+                    var containers = ResolveElementToken(token.AsElementToken(), self_copy!);
                     foreach (var c in containers)
                     {
                         handler(c);
@@ -79,7 +79,7 @@ namespace DOM.DSL.Services
                 }
                 else if (token is TBlockToken)
                 {
-                    var containers = ResolveBlockToken(token.AsBlockToken(), self_copy);
+                    var containers = ResolveBlockToken(token.AsBlockToken(), self_copy!);
                     foreach (var c in containers)
                     {
                         handler(c);
@@ -89,13 +89,13 @@ namespace DOM.DSL.Services
             }
             finally
             {
-                Factory.Release(self_copy);
+                Factory.Release(self_copy!);
             }
         }
 
-        private TContainer[] ResolveElementToken(TElementToken token, TContainer self = null)
+        private TContainer[] ResolveElementToken(TElementToken token, TContainer self = null!)
         {
-            TContainer container = null;
+            TContainer container = null!;
             switch (token.ElementName.Trim().ToLowerInvariant())
             {
                 // External
@@ -147,7 +147,7 @@ namespace DOM.DSL.Services
                 case "content": container = Factory.Get(new TContentElement(_document)); break;
                 case "aside": container = Factory.Get(_document.Attachments); break;
                 case "assotiations": container = Factory.Get(_document.Assotiations); break;
-                case "null": container = Factory.Get(null); break;
+                case "null": container = Factory.Get(null!); break;
                 case "empty": container = Factory.Get(string.Empty); break;
 
                 // Blocks
@@ -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)
             {
@@ -184,7 +184,7 @@ namespace DOM.DSL.Services
 
         private TContainer ResolvePropertyToken(TPropertyToken token, TContainer container)
         {
-            string property_index = null;
+            string property_index = null!;
             Resolve(token.PropertyIndex, c => property_index = c.ToString());
             container.MoveToProperty(token.PropertyName, property_index);
             if (token.NextToken is TPropertyToken)
@@ -223,13 +223,13 @@ namespace DOM.DSL.Services
             return container;
         }
 
-        private IEnumerable<TContainer> ResolveBlockToken(TBlockToken blockToken, TContainer self_parent = null)
+        private IEnumerable<TContainer> ResolveBlockToken(TBlockToken blockToken, TContainer self_parent = null!)
         {
             switch (blockToken.Name)
             {
                 case "block":
                     {
-                        string name = null;
+                        string name = null!;
                         Resolve(blockToken.Condition, c => name = c.ToString(), true);
                         if (false == string.IsNullOrWhiteSpace(name))
                         {
@@ -254,19 +254,19 @@ namespace DOM.DSL.Services
                         if (success)
                         {
                             var ls = self_parent == null ? null : Factory.Get(self_parent.Current, self_parent.Index);
-                            result = ResolveSimpleBlockToken(blockToken, ls);
+                            result = ResolveSimpleBlockToken(blockToken, ls!);
                             Factory.Release(ls);
                         }
                         else
                         {
-                            result = new List<TContainer> { Factory.Get(null) };
+                            result = new List<TContainer> { Factory.Get(null!) };
                         }
                         return result;
                     }
                 case "for":
                     {
                         var list = new List<TContainer>();
-                        TContainer self_container = null;
+                        TContainer self_container = null!;
                         Resolve(blockToken.Condition, c => self_container = c, false, self_parent);
                         if (self_container != null)
                         {
@@ -292,14 +292,14 @@ namespace DOM.DSL.Services
                                 }
                             }
                         }
-                        Factory.Release(self_container);
+                        Factory.Release(self_container!);
                         return list;
                     }
             }
             return ResolveSimpleBlockToken(blockToken, self_parent);
         }
 
-        private List<TContainer> ResolveSimpleBlockToken(TBlockToken token, TContainer self = null)
+        private List<TContainer> ResolveSimpleBlockToken(TBlockToken token, TContainer self = null!)
         {
             var block = new List<TContainer>();
             foreach (var t in token.Body)
@@ -319,23 +319,26 @@ namespace DOM.DSL.Services
                 {
                     var function = token.AsElementToken()?.NextToken?.AsFunctionToken();
                     var elementName = token.AsElementToken()?.ElementName;
-                    var functionName = function?.FunctionName;
-                    var rule_token = function?.FunctionArgs == null ?
-                        null :
-                        new TBlockToken(function.FunctionArgs.Select(a => a.Clone()));
-                    string special = null;
-                    if (functionName.Equals("special", StringComparison.OrdinalIgnoreCase))
+                    if (elementName != null)
                     {
-                        var args = new List<TContainer>();
-                        foreach (var a in function.FunctionArgs)
+                        var functionName = function?.FunctionName ?? string.Empty;
+                        var rule_token = function?.FunctionArgs == null ?
+                            null :
+                            new TBlockToken(function.FunctionArgs.Select(a => a.Clone()));
+                        string special = null!;
+                        if (functionName.Equals("special", StringComparison.OrdinalIgnoreCase))
                         {
-                            Resolve(a, c => args.Add(c), false);
+                            var args = new List<TContainer>();
+                            foreach (var a in function?.FunctionArgs ?? Enumerable.Empty<TToken>())
+                            {
+                                Resolve(a, c => args.Add(c), false);
+                            }
+                            special = string.Join(",", args.Select(a => a.ToString()));
+                            foreach (var a in args)
+                                Factory.Release(a);
                         }
-                        special = string.Join(",", args.Select(a => a.ToString()));
-                        foreach (var a in args)
-                            Factory.Release(a);
+                        rules.UpdateRule(elementName, functionName, rule_token!, special);
                     }
-                    rules.UpdateRule(elementName, functionName, rule_token, special);
                 }
             }
             return Factory.Get(DocumentContentReader.ReadAs<string>(_document, new TContentToStringConverter(this, rules)));
@@ -399,7 +402,7 @@ namespace DOM.DSL.Services
                     }
                     break;
             }
-            foreach (var a in args)
+            foreach (var a in args!)
             {
                 Factory.Release(a);
             }

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

@@ -15,20 +15,20 @@ namespace DOM.DSL.Tokens
             IEnumerable<TToken> body)
         {
             Name = name;
-            Condition = condition?.Clone();
+            Condition = condition?.Clone()!;
             Body = body.Select(b => b.Clone()).ToArray();
         }
 
         public TBlockToken(IEnumerable<TToken> body)
         {
             Name = string.Empty;
-            Condition = null;
+            Condition = null!;
             Body = body.Select(b => b.Clone()).ToArray();
         }
 
         public override TToken Clone()
         {
-            return new TBlockToken(this.Name, this.Condition?.Clone(), this.Body?.Select(b => b.Clone()).ToArray());
+            return new TBlockToken(this.Name, this.Condition?.Clone()!, this.Body?.Select(b => b.Clone()!).ToArray()!);
         }
 
         public override TToken CloneLocal()

ZeroLevel/Services/DOM/Model/DescriptiveMetadata.cs

@@ -96,7 +96,7 @@ namespace ZeroLevel.DocumentObjectModel
         {
             this.Byline = reader.ReadString();
             this.CopyrightNotice = reader.ReadString();
-            this.Created = reader.ReadDateTime().Value;
+            this.Created = reader.ReadDateTime()!.Value;
             this.Headers = reader.ReadCollection<Header>();
             this.Language = reader.ReadString();
             this.Original = new Tag();

ZeroLevel/Services/DOM/Model/Document.cs

@@ -20,12 +20,14 @@ namespace ZeroLevel.DocumentObjectModel
 
         public Document()
         {
-            Id = Guid.NewGuid(); Initialize();
+            Id = Guid.NewGuid(); 
+            Initialize();
         }
 
         public Document(Guid id)
         {
-            Id = id; Initialize();
+            Id = id; 
+            Initialize();
         }
 
         public Document(IBinaryReader reader)

ZeroLevel/Services/DOM/Model/Flow/Audioplayer.cs

@@ -20,6 +20,8 @@ namespace ZeroLevel.DocumentObjectModel.Flow
             Deserialize(reader);
         }
 
+        public void SetTitle(Text title) => this.Title = title;
+
         public override void Deserialize(IBinaryReader reader)
         {
             Title = reader.Read<Text>();

ZeroLevel/Services/DOM/Model/Flow/Gallery.cs

@@ -17,6 +17,8 @@ namespace ZeroLevel.DocumentObjectModel.Flow
             Deserialize(reader);
         }
 
+        public void SetTitle(Text title) => this.Title = title;
+
         public override void Deserialize(IBinaryReader reader)
         {
             Title = reader.Read<Text>();

ZeroLevel/Services/DOM/Model/Flow/Table.cs

@@ -11,7 +11,8 @@ namespace ZeroLevel.DocumentObjectModel.Flow
         public List<Column> Columns = new List<Column>();
         public List<Row> Rows = new List<Row>();
 
-        public Table() : base(ContentElementType.Table)
+        public Table()
+            : base(ContentElementType.Table)
         {
         }
 

ZeroLevel/Services/DOM/Model/Flow/Videoplayer.cs

@@ -20,6 +20,8 @@ namespace ZeroLevel.DocumentObjectModel.Flow
             Deserialize(reader);
         }
 
+        public void SetTitle(Text title) => this.Title = title;
+
         public override void Deserialize(IBinaryReader reader)
         {
             Title = reader.Read<Text>();

ZeroLevel/Services/DOM/Services/ContentBuilder.cs

@@ -185,62 +185,62 @@ namespace DOM.Services
             switch (current.Type)
             {
                 case ContentElementType.Section:
-                    (current as Section).Parts.Add(element);
+                    (current as Section)?.Parts?.Add(element);
                     break;
 
                 case ContentElementType.Paragraph:
-                    (current as Paragraph).Parts.Add(element);
+                    (current as Paragraph)?.Parts?.Add(element);
                     break;
 
                 case ContentElementType.List:
-                    (current as List).Items.Add(element);
+                    (current as List)?.Items?.Add(element);
                     break;
 
                 case ContentElementType.Row:
-                    (current as Row).Cells.Add(element);
+                    (current as Row)?.Cells?.Add(element);
                     break;
 
                 case ContentElementType.Audioplayer:
                     if (element.Type == ContentElementType.Text)
                     {
-                        (current as Audioplayer).Title = element as ZeroLevel.DocumentObjectModel.Flow.Text;
+                        (current as Audioplayer)?.SetTitle((element as ZeroLevel.DocumentObjectModel.Flow.Text)!);
                     }
                     else
                     {
-                        (current as Audioplayer).Tracks.Add(element as Audio);
+                        (current as Audioplayer)?.Tracks?.Add((element as Audio)!);
                     }
                     break;
 
                 case ContentElementType.Videoplayer:
                     if (element.Type == ContentElementType.Text)
                     {
-                        (current as Videoplayer).Title = element as ZeroLevel.DocumentObjectModel.Flow.Text;
+                        (current as Videoplayer)?.SetTitle((element as ZeroLevel.DocumentObjectModel.Flow.Text)!);
                     }
                     else
                     {
-                        (current as Videoplayer).Playlist.Add(element as Video);
+                        (current as Videoplayer)?.Playlist?.Add((element as Video)!);
                     }
                     break;
 
                 case ContentElementType.Gallery:
                     if (element.Type == ContentElementType.Text)
                     {
-                        (current as Gallery).Title = element as ZeroLevel.DocumentObjectModel.Flow.Text;
+                        (current as Gallery)?.SetTitle((element as ZeroLevel.DocumentObjectModel.Flow.Text)!);
                     }
                     else
                     {
-                        (current as Gallery).Images.Add(element as Image);
+                        (current as Gallery)?.Images?.Add((element as Image)!);
                     }
                     break;
 
                 case ContentElementType.Table:
                     if (element.Type == ContentElementType.Column)
                     {
-                        (current as Table).Columns.Add(element as Column);
+                        (current as Table)?.Columns?.Add((element as Column)!);
                     }
                     else if (element.Type == ContentElementType.Row)
                     {
-                        (current as Table).Rows.Add(element as Row);
+                        (current as Table)?.Rows?.Add((element as Row)!);
                     }
                     break;
             }

ZeroLevel/Services/DOM/Services/DocumentContentReader.cs

@@ -17,132 +17,156 @@ namespace DOM.Services
             {
                 // Primitives
                 case ContentElementType.Text:
-                    reader.ReadText(element as ZeroLevel.DocumentObjectModel.Flow.Text);
+                    reader.ReadText((element as ZeroLevel.DocumentObjectModel.Flow.Text)!);
                     break;
 
                 case ContentElementType.Quote:
-                    reader.ReadQuote(element as Quote);
+                    reader.ReadQuote((element as Quote)!);
                     break;
 
                 case ContentElementType.Link:
                     counter.IncLinkId();
-                    reader.ReadLink(element as Link, counter.LinkId);
+                    reader.ReadLink((element as Link)!, counter.LinkId);
                     break;
 
                 case ContentElementType.Image:
                     counter.IncImageId();
-                    reader.ReadImage(element as Image, counter.ImageId);
+                    reader.ReadImage((element as Image)!, counter.ImageId);
                     break;
 
                 case ContentElementType.Audio:
                     counter.IncAudioId();
-                    reader.ReadAudio(element as Audio, counter.AudioId);
+                    reader.ReadAudio((element as Audio)!, counter.AudioId);
                     break;
 
                 case ContentElementType.Video:
                     counter.IncVideoId();
-                    reader.ReadVideo(element as Video, counter.VideoId);
+                    reader.ReadVideo((element as Video)!, counter.VideoId);
                     break;
 
                 case ContentElementType.Form:
-                    reader.ReadForm(element as FormContent);
+                    reader.ReadForm((element as FormContent)!);
                     break;
 
                 // Containers
                 case ContentElementType.Content:
                     {
                         var content = (element as FlowContent);
-                        for (int i = 0; i < content.Sections.Count; i++)
+                        if (content != null)
                         {
-                            TraversElement(content.Sections[i], reader, counter);
+                            for (int i = 0; i < content.Sections.Count; i++)
+                            {
+                                TraversElement(content.Sections[i], reader, counter);
+                            }
                         }
                     }
                     break;
 
                 case ContentElementType.Section:
                     var section = (element as Section);
-                    reader.EnterSection(section);
-                    for (int i = 0; i < section.Parts.Count; i++)
+                    if (section != null)
                     {
-                        TraversElement(section.Parts[i], reader, counter);
+                        reader.EnterSection(section);
+                        for (int i = 0; i < section.Parts.Count; i++)
+                        {
+                            TraversElement(section.Parts[i], reader, counter);
+                        }
+                        reader.LeaveSection(section);
                     }
-                    reader.LeaveSection(section);
                     break;
 
                 case ContentElementType.Paragraph:
                     var paragraph = (element as Paragraph);
-                    reader.EnterParagraph(paragraph);
-                    for (int i = 0; i < paragraph.Parts.Count; i++)
+                    if (paragraph != null)
                     {
-                        TraversElement(paragraph.Parts[i], reader, counter);
+                        reader.EnterParagraph(paragraph);
+                        for (int i = 0; i < paragraph.Parts.Count; i++)
+                        {
+                            TraversElement(paragraph.Parts[i], reader, counter);
+                        }
+                        reader.LeaveParagraph(paragraph);
                     }
-                    reader.LeaveParagraph(paragraph);
                     break;
 
                 case ContentElementType.List:
                     var list = (element as List);
-                    reader.EnterList(list);
-                    for (int i = 0; i < list.Items.Count; i++)
+                    if (list != null)
                     {
-                        reader.EnterListItem(list, list.Items[i], i);
-                        TraversElement(list.Items[i], reader, counter);
-                        reader.LeaveListItem(list, list.Items[i], i);
+                        reader.EnterList(list);
+                        for (int i = 0; i < list.Items.Count; i++)
+                        {
+                            reader.EnterListItem(list, list.Items[i], i);
+                            TraversElement(list.Items[i], reader, counter);
+                            reader.LeaveListItem(list, list.Items[i], i);
+                        }
+                        reader.LeaveList(list);
                     }
-                    reader.LeaveList(list);
                     break;
 
                 case ContentElementType.Gallery:
                     var gallery = (element as Gallery);
-                    reader.EnterGallery(gallery);
-                    for (int i = 0; i < gallery.Images.Count; i++)
+                    if (gallery != null)
                     {
-                        reader.ReadImage(gallery.Images[i], i);
+                        reader.EnterGallery(gallery);
+                        for (int i = 0; i < gallery.Images.Count; i++)
+                        {
+                            reader.ReadImage(gallery.Images[i], i);
+                        }
+                        reader.LeaveGallery(gallery);
                     }
-                    reader.LeaveGallery(gallery);
                     break;
 
                 case ContentElementType.Audioplayer:
                     var audioplayer = (element as Audioplayer);
-                    reader.EnterAudioplayer(audioplayer);
-                    for (int i = 0; i < audioplayer.Tracks.Count; i++)
+                    if (audioplayer != null)
                     {
-                        reader.ReadAudio(audioplayer.Tracks[i], i);
+                        reader.EnterAudioplayer(audioplayer);
+                        for (int i = 0; i < audioplayer.Tracks.Count; i++)
+                        {
+                            reader.ReadAudio(audioplayer.Tracks[i], i);
+                        }
+                        reader.LeaveAudioplayer(audioplayer);
                     }
-                    reader.LeaveAudioplayer(audioplayer);
                     break;
 
                 case ContentElementType.Videoplayer:
                     var videoplayer = (element as Videoplayer);
-                    reader.EnterVideoplayer(videoplayer);
-                    for (int i = 0; i < videoplayer.Playlist.Count; i++)
+                    if (videoplayer != null)
                     {
-                        reader.ReadVideo(videoplayer.Playlist[i], i);
+                        reader.EnterVideoplayer(videoplayer);
+                        for (int i = 0; i < videoplayer.Playlist.Count; i++)
+                        {
+                            reader.ReadVideo(videoplayer.Playlist[i], i);
+                        }
+                        reader.LeaveVideoplayer(videoplayer);
                     }
-                    reader.LeaveVideoplayer(videoplayer);
                     break;
 
                 case ContentElementType.Table:
                     var table = (element as Table);
-                    reader.EnterTable(table);
-                    reader.EnterColumns(table);
-                    for (int i = 0; i < table.Columns.Count; i++)
+                    if (table != null)
                     {
-                        reader.ReadColumn(table, table.Columns[i], i);
-                    }
-                    reader.LeaveColumns(table);
-                    for (int ri = 0; ri < table.Rows.Count; ri++)
-                    {
-                        var row = table.Rows[ri];
-                        reader.EnterRow(table, row, ri);
-                        for (int i = 0; i < row.Cells.Count; i++)
+                        reader.EnterTable(table);
+                        reader.EnterColumns(table);
+                        for (int i = 0; i < table.Columns.Count; i++)
+                        {
+                            reader.ReadColumn(table, table.Columns[i], i);
+                        }
+                        reader.LeaveColumns(table);
+                        for (int ri = 0; ri < table.Rows.Count; ri++)
                         {
-                            reader.EnterRowCell(table, row, row.Cells[i], i);
-                            TraversElement(row.Cells[i], reader, counter);
-                            reader.LeaveRowCell(table, row, row.Cells[i], i);
+                            var row = table.Rows[ri];
+                            reader.EnterRow(table, row, ri);
+                            for (int i = 0; i < row.Cells.Count; i++)
+                            {
+                                reader.EnterRowCell(table, row, row.Cells[i], i);
+                                TraversElement(row.Cells[i], reader, counter);
+                                reader.LeaveRowCell(table, row, row.Cells[i], i);
+                            }
+                            reader.LeaveRow(table, row, ri);
                         }
-                        reader.LeaveRow(table, row, ri);
+                        reader.LeaveTable(table);
                     }
-                    reader.LeaveTable(table);
                     break;
             }
         }

ZeroLevel/Services/DependencyInjection/Container.cs

@@ -7,7 +7,7 @@ using System.Threading;
 using ZeroLevel.Services.Collections;
 
 namespace ZeroLevel.DependencyInjection
-{    
+{
     internal sealed class Container :
         IContainer
     {
@@ -15,29 +15,30 @@ namespace ZeroLevel.DependencyInjection
 
         private static object Activate(Type type, object[] args)
         {
+            if (type == null) return null!;
             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);
         }
 
         public T CreateInstance<T>(string resolveName = "")
         {
-            T instance = default(T);
+            T instance = default(T)!;
             try
             {
                 instance = Resolve<T>(resolveName);
             }
             catch
             {
-                instance = (T)Activate(typeof(T), null);
+                instance = (T)Activate(typeof(T), null!);
             }
-            Compose(instance);
+            Compose(instance!);
             return instance;
         }
 
         public T CreateInstance<T>(object[] args, string resolveName = "")
         {
-            T instance = default(T);
+            T instance = default(T)!;
             try
             {
                 instance = Resolve<T>(resolveName, args);
@@ -46,20 +47,20 @@ namespace ZeroLevel.DependencyInjection
             {
                 instance = (T)Activate(typeof(T), args);
             }
-            Compose(instance);
+            Compose(instance!);
             return instance;
         }
 
         public object CreateInstance(Type type, string resolveName = "")
         {
-            object instance = null;
+            object instance = null!;
             try
             {
                 instance = Resolve(type, resolveName);
             }
             catch
             {
-                instance = Activate(type, null);
+                instance = Activate(type, null!);
             }
             Compose(instance);
             return instance;
@@ -67,7 +68,7 @@ namespace ZeroLevel.DependencyInjection
 
         public object CreateInstance(Type type, object[] args, string resolveName = "")
         {
-            object instance = null;
+            object instance = null!;
             try
             {
                 instance = Resolve(type, resolveName, args);
@@ -258,12 +259,12 @@ namespace ZeroLevel.DependencyInjection
             }
             var resolveType = FindResolving(maybyType,
                 resolveAttribute?.ResolveName ?? string.Empty,
-                resolveAttribute?.ContractType);
+                resolveAttribute?.ContractType!);
             try
             {
                 if (is_generic)
-                    return MakeGenericResolving(resolveType, type, null);
-                return MakeResolving(resolveType, null);
+                    return MakeGenericResolving(resolveType, type, null!);
+                return MakeResolving(resolveType, null!);
             }
             catch (Exception ex)
             {
@@ -375,7 +376,7 @@ namespace ZeroLevel.DependencyInjection
                     if (_resolvingMap[contractType].
                         Any(it => it.ResolveKey.Equals(resolveType.ResolveKey, StringComparison.OrdinalIgnoreCase)))
                     {
-                        throw new Exception($"Resolve type with the same name '{resolveType.ResolveKey}' already has been defined. Contract: { contractType.FullName}");
+                        throw new Exception($"Resolve type with the same name '{resolveType.ResolveKey}' already has been defined. Contract: {contractType.FullName}");
                     }
                 }
                 try
@@ -667,7 +668,7 @@ namespace ZeroLevel.DependencyInjection
 
         #region Safe register
 
-        public bool TryRegister<TContract, TImplementation>(Action<Exception> fallback = null)
+        public bool TryRegister<TContract, TImplementation>(Action<Exception> fallback = null!)
         {
             try
             {
@@ -681,7 +682,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryRegister<TContract, TImplementation>(bool shared, Action<Exception> fallback = null)
+        public bool TryRegister<TContract, TImplementation>(bool shared, Action<Exception> fallback = null!)
         {
             try
             {
@@ -695,7 +696,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryRegister<TContract, TImplementation>(string resolveName, Action<Exception> fallback = null)
+        public bool TryRegister<TContract, TImplementation>(string resolveName, Action<Exception> fallback = null!)
         {
             try
             {
@@ -709,7 +710,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryRegister<TContract, TImplementation>(string resolveName, bool shared, Action<Exception> fallback = null)
+        public bool TryRegister<TContract, TImplementation>(string resolveName, bool shared, Action<Exception> fallback = null!)
         {
             try
             {
@@ -723,7 +724,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryRegister(Type contractType, Type implementationType, Action<Exception> fallback = null)
+        public bool TryRegister(Type contractType, Type implementationType, Action<Exception> fallback = null!)
         {
             try
             {
@@ -737,7 +738,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryRegister(Type contractType, Type implementationType, string resolveName, Action<Exception> fallback = null)
+        public bool TryRegister(Type contractType, Type implementationType, string resolveName, Action<Exception> fallback = null!)
         {
             try
             {
@@ -751,7 +752,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryRegister(Type contractType, Type implementationType, bool shared, Action<Exception> fallback = null)
+        public bool TryRegister(Type contractType, Type implementationType, bool shared, Action<Exception> fallback = null!)
         {
             try
             {
@@ -765,7 +766,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryRegister(Type contractType, Type implementationType, string resolveName, bool shared, Action<Exception> fallback = null)
+        public bool TryRegister(Type contractType, Type implementationType, string resolveName, bool shared, Action<Exception> fallback = null!)
         {
             try
             {
@@ -783,7 +784,7 @@ namespace ZeroLevel.DependencyInjection
 
         #region Safe register with parameters
 
-        public bool TryParameterizedRegister<TContract, TImplementation>(object[] constructorParameters, Action<Exception> fallback = null)
+        public bool TryParameterizedRegister<TContract, TImplementation>(object[] constructorParameters, Action<Exception> fallback = null!)
         {
             try
             {
@@ -797,7 +798,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryParameterizedRegister<TContract, TImplementation>(string resolveName, object[] constructorParameters, Action<Exception> fallback = null)
+        public bool TryParameterizedRegister<TContract, TImplementation>(string resolveName, object[] constructorParameters, Action<Exception> fallback = null!)
         {
             try
             {
@@ -811,7 +812,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryParameterizedRegister<TContract, TImplementation>(bool shared, object[] constructorParameters, Action<Exception> fallback = null)
+        public bool TryParameterizedRegister<TContract, TImplementation>(bool shared, object[] constructorParameters, Action<Exception> fallback = null!)
         {
             try
             {
@@ -825,7 +826,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryParameterizedRegister<TContract, TImplementation>(string resolveName, bool shared, object[] constructorParameters, Action<Exception> fallback = null)
+        public bool TryParameterizedRegister<TContract, TImplementation>(string resolveName, bool shared, object[] constructorParameters, Action<Exception> fallback = null!)
         {
             try
             {
@@ -839,7 +840,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryParameterizedRegister(Type contractType, Type implementationType, object[] constructorParameters, Action<Exception> fallback = null)
+        public bool TryParameterizedRegister(Type contractType, Type implementationType, object[] constructorParameters, Action<Exception> fallback = null!)
         {
             try
             {
@@ -853,7 +854,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryParameterizedRegister(Type contractType, Type implementationType, string resolveName, object[] constructorParameters, Action<Exception> fallback = null)
+        public bool TryParameterizedRegister(Type contractType, Type implementationType, string resolveName, object[] constructorParameters, Action<Exception> fallback = null!)
         {
             try
             {
@@ -867,7 +868,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryParameterizedRegister(Type contractType, Type implementationType, bool shared, object[] constructorParameters, Action<Exception> fallback = null)
+        public bool TryParameterizedRegister(Type contractType, Type implementationType, bool shared, object[] constructorParameters, Action<Exception> fallback = null!)
         {
             try
             {
@@ -881,7 +882,7 @@ namespace ZeroLevel.DependencyInjection
             }
         }
 
-        public bool TryParameterizedRegister(Type contractType, Type implementationType, string resolveName, bool shared, object[] constructorParameters, Action<Exception> fallback = null)
+        public bool TryParameterizedRegister(Type contractType, Type implementationType, string resolveName, bool shared, object[] constructorParameters, Action<Exception> fallback = null!)
         {
             try
             {
@@ -901,7 +902,7 @@ namespace ZeroLevel.DependencyInjection
 
         public object Resolve(Type type, bool compose = true)
         {
-            return Resolve(type, string.Empty, null, compose);
+            return Resolve(type, string.Empty, null!, compose);
         }
 
         public object Resolve(Type type, object[] args, bool compose = true)
@@ -911,12 +912,12 @@ namespace ZeroLevel.DependencyInjection
 
         public object Resolve(Type type, string resolveName, bool compose = true)
         {
-            return Resolve(type, resolveName, null, compose);
+            return Resolve(type, resolveName, null!, compose);
         }
 
         public T Resolve<T>(bool compose = true)
         {
-            return (T)Resolve(typeof(T), string.Empty, null, compose);
+            return (T)Resolve(typeof(T), string.Empty, null!, compose);
         }
 
         public T Resolve<T>(object[] args, bool compose = true)
@@ -926,7 +927,7 @@ namespace ZeroLevel.DependencyInjection
 
         public T Resolve<T>(string resolveName, bool compose = true)
         {
-            return (T)Resolve(typeof(T), resolveName, null, compose);
+            return (T)Resolve(typeof(T), resolveName, null!, compose);
         }
 
         public T Resolve<T>(string resolveName, object[] args, bool compose = true)
@@ -980,7 +981,7 @@ namespace ZeroLevel.DependencyInjection
             {
                 _rwLock.ExitReadLock();
             }
-            return new Tuple<ResolveTypeInfo, bool>(null, false);
+            return new Tuple<ResolveTypeInfo, bool>(null!, false);
         }
 
         public object Resolve(Type type, string resolveName, object[] args, bool compose = true)
@@ -1009,7 +1010,7 @@ namespace ZeroLevel.DependencyInjection
 
         public object TryResolve(Type type, out object result, bool compose = true)
         {
-            return TryResolve(type, string.Empty, null, out result, compose);
+            return TryResolve(type, string.Empty, null!, out result, compose);
         }
 
         public object TryResolve(Type type, object[] args, out object result, bool compose = true)
@@ -1019,18 +1020,18 @@ namespace ZeroLevel.DependencyInjection
 
         public object TryResolve(Type type, string resolveName, out object result, bool compose = true)
         {
-            return TryResolve(type, resolveName, null, out result, compose);
+            return TryResolve(type, resolveName, null!, out result, compose);
         }
 
         public bool TryResolve<T>(out T result, bool compose = true)
         {
             object instance;
-            if (TryResolve(typeof(T), string.Empty, null, out instance, compose))
+            if (TryResolve(typeof(T), string.Empty, null!, out instance, compose))
             {
                 result = (T)instance;
                 return true;
             }
-            result = default(T);
+            result = default(T)!;
             return false;
         }
 
@@ -1042,19 +1043,19 @@ namespace ZeroLevel.DependencyInjection
                 result = (T)instance;
                 return true;
             }
-            result = default(T);
+            result = default(T)!;
             return false;
         }
 
         public bool TryResolve<T>(string resolveName, out T result, bool compose = true)
         {
             object instance;
-            if (TryResolve(typeof(T), resolveName, null, out instance, compose))
+            if (TryResolve(typeof(T), resolveName, null!, out instance, compose))
             {
                 result = (T)instance;
                 return true;
             }
-            result = default(T);
+            result = default(T)!;
             return false;
         }
 
@@ -1066,7 +1067,7 @@ namespace ZeroLevel.DependencyInjection
                 result = (T)instance;
                 return true;
             }
-            result = default(T);
+            result = default(T)!;
             return false;
         }
 
@@ -1076,7 +1077,7 @@ namespace ZeroLevel.DependencyInjection
             var resolve = GetResolvedType(type, resolveName);
             if (null == resolve.Item1)
             {
-                result = null;
+                result = null!;
                 return false;
             }
             try
@@ -1096,7 +1097,7 @@ namespace ZeroLevel.DependencyInjection
                 Log.SystemWarning(
                     $"Can't create type '{type.FullName}' instance for resolve dependency with contract type '{type.FullName}' and dependency name '{resolveName}'", ex);
             }
-            result = null;
+            result = null!;
             return false;
         }
 
@@ -1109,62 +1110,71 @@ namespace ZeroLevel.DependencyInjection
         /// </summary>
         private void FillParametrizedFieldsAndProperties(object instance)
         {
-            foreach (var property in instance.GetType().GetProperties(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy))
+            if (instance != null)
             {
-                var attr = property.GetCustomAttribute<ParameterAttribute>();
-                if (attr != null)
+                foreach (var property in instance.GetType().GetProperties(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy))
                 {
-                    var parameterType = attr.Type ?? property.PropertyType;
-                    var parameterName = attr.Name ?? property.Name;
-                    property.SetValue(instance, this.Get(parameterType, parameterName));
+                    var attr = property.GetCustomAttribute<ParameterAttribute>();
+                    if (attr != null)
+                    {
+                        var parameterType = attr.Type ?? property.PropertyType;
+                        var parameterName = attr.Name ?? property.Name;
+                        property.SetValue(instance, this.Get(parameterType, parameterName));
+                    }
                 }
-            }
-            foreach (var field in instance.GetType().GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy))
-            {
-                var attr = field.GetCustomAttribute<ParameterAttribute>();
-                if (attr != null)
+                foreach (var field in instance.GetType().GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy))
                 {
-                    var parameterType = attr.Type ?? field.FieldType;
-                    var parameterName = string.IsNullOrWhiteSpace(attr.Name) ? field.Name : attr.Name;
-                    field.SetValue(instance, this.Get(parameterType, parameterName));
+                    var attr = field.GetCustomAttribute<ParameterAttribute>();
+                    if (attr != null)
+                    {
+                        var parameterType = attr.Type ?? field.FieldType;
+                        var parameterName = string.IsNullOrWhiteSpace(attr.Name) ? field.Name : attr.Name;
+                        field.SetValue(instance, this.Get(parameterType, parameterName));
+                    }
                 }
             }
         }
 
         private void ComposeParts(object instance)
         {
-            var resolve_properties = CollectResolvingProperties(instance.GetType());
-            var resolve_fields = CollectResolvingFields(instance.GetType());
-            foreach (var p in resolve_properties)
-            {
-                var resolve_instance = MakeInstanceBy(p.PropertyType,
-                    p.GetCustomAttribute<ResolveAttribute>());
-                p.SetValue(instance, resolve_instance);
-            }
-            foreach (var f in resolve_fields)
+            if (instance != null)
             {
-                var resolve_instance = MakeInstanceBy(f.FieldType,
-                    f.GetCustomAttribute<ResolveAttribute>());
-                f.SetValue(instance, resolve_instance);
+                var resolve_properties = CollectResolvingProperties(instance.GetType());
+                var resolve_fields = CollectResolvingFields(instance.GetType());
+                foreach (var p in resolve_properties)
+                {
+                    var resolve_instance = MakeInstanceBy(p.PropertyType,
+                        p.GetCustomAttribute<ResolveAttribute>());
+                    p.SetValue(instance, resolve_instance);
+                }
+                foreach (var f in resolve_fields)
+                {
+                    var resolve_instance = MakeInstanceBy(f.FieldType,
+                        f.GetCustomAttribute<ResolveAttribute>());
+                    f.SetValue(instance, resolve_instance);
+                }
             }
             FillParametrizedFieldsAndProperties(instance);
         }
 
         private void RecursiveCompose(object instance, HashSet<object> set)
         {
-            foreach (var f in
+            if (instance != null)
+            {
+                foreach (var f in
                 instance.GetType().GetFields(BindingFlags.Public |
                 BindingFlags.NonPublic |
                 BindingFlags.Instance))
-            {
-                if (f.FieldType.IsClass || f.FieldType.IsInterface)
                 {
-                    var next = f.GetValue(instance);
-                    if (null != next)
+                    if (f.FieldType.IsClass || f.FieldType.IsInterface)
                     {
-                        if (set.Add(next))
+                        var next = f.GetValue(instance);
+                        if (null != next)
                         {
-                            RecursiveCompose(next, set);
+                            if (set.Add(next))
+                            {
+                                RecursiveCompose(next, set);
+                            }
                         }
                     }
                 }
@@ -1219,7 +1229,7 @@ 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)
                             {

ZeroLevel/Services/FileSystem/FSUtils.cs

@@ -275,7 +275,7 @@ namespace ZeroLevel.Services.FileSystem
         /// </summary>
         public static bool IsFileLocked(FileInfo file)
         {
-            FileStream fileStream = null;
+            FileStream fileStream = null!;
             try
             {
                 fileStream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None);
@@ -291,14 +291,14 @@ namespace ZeroLevel.Services.FileSystem
                     fileStream.Close();
                     fileStream.Dispose();
                 }
-                file = null;
+                file = null!;
             }
             return false;
         }
 
         public static bool IsFileLocked(string file)
         {
-            FileStream fileStream = null;
+            FileStream fileStream = null!;
             try
             {
                 fileStream = File.Open(file, FileMode.Open, FileAccess.Read, FileShare.None);
@@ -314,7 +314,7 @@ namespace ZeroLevel.Services.FileSystem
                     fileStream.Close();
                     fileStream.Dispose();
                 }
-                file = null;
+                file = null!;
             }
             return false;
         }

ZeroLevel/Services/FileSystem/PeriodicFileSystemWatcher.cs

@@ -65,7 +65,7 @@ namespace ZeroLevel.Services.FileSystem
 
         private void CheckSourceFolder()
         {
-            string[] files = null;
+            string[] files = null!;
             try
             {
                 files = GetFilesFromSource();

ZeroLevel/Services/IL.cs

@@ -172,7 +172,7 @@ namespace ZeroLevel.Services
             var returnType = method.ReturnType;
             var parametersTypes = method.GetParameters().Select(p => p.ParameterType).ToArray();
             var hasReturnValue = returnType != typeof(void);
-            MethodBuilder dynamicMethod = null;
+            MethodBuilder dynamicMethod = null!;
             switch (methodType)
             {
                 case MethodType.DirectProxy:

ZeroLevel/Services/Invokation/InvokeWrapper.cs

@@ -157,8 +157,12 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(filter)
                 ?.Select(method => method.MakeGenericMethod(typeof(T))).Select(CreateCompiledExpression);
-            Configure(result);
-            return result.Select(r => r.Item1).ToList();
+            if (result != null)
+            {
+                Configure(result);
+                return result.Select(r => r.Item1).ToList();
+            }
+            return Enumerable.Empty<string>();
         }
 
         public IEnumerable<string> ConfigureGeneric(Type instanceType, Type genericType, Func<MethodInfo, bool> filter)
@@ -169,8 +173,12 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(filter)
                 ?.Select(method => method.MakeGenericMethod(genericType)).Select(CreateCompiledExpression);
-            Configure(result);
-            return result.Select(r => r.Item1).ToList();
+            if (result != null)
+            {
+                Configure(result);
+                return result.Select(r => r.Item1).ToList();
+            }
+            return Enumerable.Empty<string>();
         }
 
         public IEnumerable<string> Configure(Type instanceType, Func<MethodInfo, bool> filter)
@@ -181,8 +189,12 @@ namespace ZeroLevel.Services.Invokation
                                          BindingFlags.NonPublic |
                                          BindingFlags.FlattenHierarchy)?.Where(filter)
                 ?.Select(CreateCompiledExpression);
-            Configure(result);
-            return result.Select(r => r.Item1).ToList();
+            if (result != null)
+            {
+                Configure(result);
+                return result.Select(r => r.Item1).ToList();
+            }
+            return Enumerable.Empty<string>();
         }
 
         #endregion Configure by Type

ZeroLevel/Services/Logging/Implementation/EncryptedFileLog.cs

@@ -112,7 +112,7 @@ namespace ZeroLevel.Logging
             {
                 var nextFileName = GetNextFileName();
                 CloseCurrentWriter();
-                Stream stream = null;
+                Stream stream = null!;
                 try
                 {
                     _currentLogFile = nextFileName;

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

@@ -74,20 +74,20 @@ 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()
             {
                 _parent?.Dispose();
-                _parent = default;
+                _parent = default!;
                 
                 _hashset?.Dispose();
-                _hashset = default;
+                _hashset = default!;
                 
-                _src = default;
-                _selector = default;
+                _src = default!;
+                _selector = default!;
                 Pool<DistinctExprEnumerator>.Return(this);
             }
         }

ZeroLevel/Services/MemoryPools/Collections/Specialized/LocalList.cs

@@ -16,8 +16,8 @@ namespace MemoryPools.Collections.Specialized
 		private IList<T> _other;
 
 		// Static lists to store real length (-1 field in struct)
-		private static readonly IList<T> LengthIs1 = new List<T> {default};
-		private static readonly IList<T> LengthIs2 = new List<T> {default, default};
+		private static readonly IList<T> LengthIs1 = new List<T> {default!};
+		private static readonly IList<T> LengthIs2 = new List<T> {default!, default!};
 
 		private const int DefaultListCapacity = 8;
 		public const int LocalStoreCapacity = 2;
@@ -238,7 +238,7 @@ namespace MemoryPools.Collections.Specialized
 					throw new IndexOutOfRangeException();
 
 				if (_other?.Count > LocalStoreCapacity) return _other[index];
-				if (_other.Count > 0 && index == 0) return _items.Item1;
+				if (_other!.Count > 0 && index == 0) return _items.Item1;
 				if (_other.Count > 1 && index == 1) return _items.Item2;
 
 				throw new InvalidOperationException("Uncovered branch");

ZeroLevel/Services/Semantic/Trie.cs

@@ -76,7 +76,7 @@ namespace ZeroLevel.Services.Semantic
             }
             internal uint? GetKey(string word, int index)
             {
-                if (this.Children?.ContainsKey(word[index]) ?? false)
+                if (word != null && (this.Children?.ContainsKey(word[index]) ?? false))
                 {
                     if (word.Length == index + 1) return this.Children[word[index]].Value;
                     return this.Children[word[index]].GetKey(word, index + 1);
@@ -103,7 +103,7 @@ namespace ZeroLevel.Services.Semantic
 
             internal void DestroyReverseIndex()
             {
-                this.Parent = null;
+                this.Parent = null!;
                 this.Key = null;
                 if (this.Children != null)
                 {
@@ -189,7 +189,7 @@ namespace ZeroLevel.Services.Semantic
             {
                 do
                 {
-                    yield return node.Key.Value;
+                    yield return node.Key!.Value;
                     node = node.Parent;
                 } while (node.Parent != null);
             }
@@ -198,7 +198,7 @@ namespace ZeroLevel.Services.Semantic
         public bool Contains(string word)
         {
             if (word?.Length == 0) return false;
-            return _root.GetKey(word, 0).HasValue;
+            return _root.GetKey(word!, 0).HasValue;
         }
 
         public void Serialize(IBinaryWriter writer)
@@ -224,7 +224,7 @@ namespace ZeroLevel.Services.Semantic
                 {
                     _reverse_index = new Dictionary<uint, TrieNode>();
                 }
-                _root.RebuildReverseIndex(null, ' ', _reverse_index);
+                _root.RebuildReverseIndex(null!, ' ', _reverse_index);
             }
         }
 
@@ -233,7 +233,7 @@ namespace ZeroLevel.Services.Semantic
             if (_reverse_index != null)
             {
                 _reverse_index.Clear();
-                _reverse_index = null;
+                _reverse_index = null!;
             }
             _root.DestroyReverseIndex();
         }

ZeroLevel/Services/Serialization/MessageSerializer.cs

@@ -213,12 +213,12 @@ namespace ZeroLevel.Services.Serialization
 
         public static T DeserializeCompatible<T>(byte[] data)
         {
-            if (data == null || data.Length == 0) return default(T);
+            if (data == null || data.Length == 0) return default(T)!;
             if (typeof(IBinarySerializable).IsAssignableFrom(typeof(T)))
             {
                 using (var reader = new MemoryStreamReader(data))
                 {
-                    var direct = (IBinarySerializable)Activator.CreateInstance<T>();
+                    var direct = (IBinarySerializable)Activator.CreateInstance<T>()!;
                     direct.Deserialize(reader);
                     return (T)direct;
                 }
@@ -233,7 +233,7 @@ namespace ZeroLevel.Services.Serialization
         {
             if (typeof(IBinarySerializable).IsAssignableFrom(typeof(T)))
             {
-                var direct = (IBinarySerializable)Activator.CreateInstance<T>();
+                var direct = (IBinarySerializable)Activator.CreateInstance<T>()!;
                 direct.Deserialize(reader);
                 return (T)direct;
             }
@@ -243,16 +243,16 @@ namespace ZeroLevel.Services.Serialization
         {
             if (typeof(IAsyncBinarySerializable).IsAssignableFrom(typeof(T)))
             {
-                var direct = (IAsyncBinarySerializable)Activator.CreateInstance<T>();
+                var direct = (IAsyncBinarySerializable)Activator.CreateInstance<T>()!;
                 await direct.DeserializeAsync(reader);
                 return (T)direct;
             }
-            return PrimitiveTypeSerializer.Deserialize<T>(reader as IBinaryReader);
+            return PrimitiveTypeSerializer.Deserialize<T>((reader as IBinaryReader)!);
         }
 
         public static object DeserializeCompatible(Type type, byte[] data)
         {
-            if (data == null || data.Length == 0) return null;
+            if (data == null || data.Length == 0) return null!;
             if (typeof(IBinarySerializable).IsAssignableFrom(type))
             {
                 using (var reader = new MemoryStreamReader(data))
@@ -271,7 +271,7 @@ namespace ZeroLevel.Services.Serialization
         public static T Copy<T>(T value)
             where T : IBinarySerializable
         {
-            if (null == value) return default;
+            if (null == value) return default!;
             using (var writer = new MemoryStreamWriter())
             {
                 value.Serialize(writer);
@@ -290,10 +290,10 @@ namespace ZeroLevel.Services.Serialization
             {
                 using (var writer = new MemoryStreamWriter())
                 {
-                    ((IBinarySerializable)value).Serialize(writer);
+                    (value as IBinarySerializable)?.Serialize(writer);
                     using (var reader = new MemoryStreamReader(writer.Complete()))
                     {
-                        var direct = (IBinarySerializable)Activator.CreateInstance<T>();
+                        var direct = (IBinarySerializable)Activator.CreateInstance<T>()!;
                         direct.Deserialize(reader);
                         return (T)direct;
                     }

ZeroLevel/Services/Specification/Services/SpecificationBuilder.cs

@@ -81,14 +81,14 @@ namespace ZeroLevel.Specification
                     case SpecificationConstructorParameterKind.Tree:
                         var tree = (ITree)_values[i].Value;
                         var list = new List<object>();
-                        Action<ITreeNode> visitor = null;
+                        Action<ITreeNode> visitor = null!;
                         visitor = new Action<ITreeNode>(node =>
                         {
                             if (node.IsSelected)
                             {
                                 if (node.Tag != null || _values[i].ParameterType.GetElementType() != typeof(string))
                                 {
-                                    list.Add(node.Tag);
+                                    list.Add(node.Tag!);
                                 }
                                 else
                                 {
@@ -116,7 +116,7 @@ namespace ZeroLevel.Specification
 
         public override bool Equals(object obj)
         {
-            return this.Equals(obj as ISpecificationBuilder);
+            return this.Equals((obj as ISpecificationBuilder)!);
         }
 
         public bool Equals(ISpecificationBuilder other)

ZeroLevel/Services/Web/UrlBuilder.cs

@@ -20,7 +20,7 @@ namespace ZeroLevel.Services.Web
         {
             if (null == instance)
             {
-                return BuildRequestUrl(baseUri, resource, null);
+                return BuildRequestUrl(baseUri, resource, null!);
             }
             var members = typeof(T).GetMembers(
                 BindingFlags.Public |
@@ -34,10 +34,10 @@ namespace ZeroLevel.Services.Web
                 switch (member.MemberType)
                 {
                     case MemberTypes.Property:
-                        parameters.Add(member.Name.ToLowerInvariant(), (member as PropertyInfo).GetValue(instance));
+                        parameters.Add(member.Name.ToLowerInvariant(), (member as PropertyInfo)!.GetValue(instance));
                         break;
                     case MemberTypes.Field:
-                        parameters.Add(member.Name.ToLowerInvariant(), (member as FieldInfo).GetValue(instance));
+                        parameters.Add(member.Name.ToLowerInvariant(), (member as FieldInfo)!.GetValue(instance));
                         break;
                     default:
                         continue;

ZeroLevel/Services/Web/UrlUtility.cs

@@ -497,8 +497,8 @@ namespace ZeroLevel.Services.Web
                     i++;
                 }
                 // extract the name / value pair
-                string name = null;
-                string value = null;
+                string name = null!;
+                string value = null!;
                 if (ti >= 0)
                 {
                     name = s.Substring(si, ti - si);

ZeroLevel/ZeroLevel.csproj

@@ -6,14 +6,37 @@
 		<Nullable>enable</Nullable>
 		<ApplicationIcon>lz.ico</ApplicationIcon>
 		<AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+		<Title>ZeroLevel</Title>
+		<FileVersion>4.0.0.0</FileVersion>
+		<AssemblyVersion>4.0.0.0</AssemblyVersion>
+		<AnalysisLevel>latest</AnalysisLevel>
+		<Version>$(AssemblyVersion)</Version>
+		<Authors>Ogoun</Authors>
+		<Description>Basic Toolkit.</Description>
+		<Copyright>© ogoun</Copyright>
+		<PackageProjectUrl>https://github.com/ogoun/Zero</PackageProjectUrl>
+		<PackageIcon>lz.ico</PackageIcon>
+		<RepositoryUrl>https://github.com/ogoun/Zero</RepositoryUrl>
+		<RepositoryType>git</RepositoryType>
+	</PropertyGroup>
+
+	<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
+	  <NoWarn>1701;1702;8618</NoWarn>
+	</PropertyGroup>
+
+	<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+	  <NoWarn>1701;1702;8618</NoWarn>
 	</PropertyGroup>
 
 	<ItemGroup>
-		<None Remove="lz.ico" />
+		<Content Include="lz.ico" />
 	</ItemGroup>
 
 	<ItemGroup>
-		<Content Include="lz.ico" />
+	  <None Update="lz.ico">
+	    <Pack>True</Pack>
+	    <PackagePath>\</PackagePath>
+	  </None>
 	</ItemGroup>
 
 </Project>