diff --git a/src/GDShrapt.Converter.Tests/ConversionTests.cs b/src/GDShrapt.Converter.Tests/ConversionTests.cs
index 3cacd8c..c24c3e8 100644
--- a/src/GDShrapt.Converter.Tests/ConversionTests.cs
+++ b/src/GDShrapt.Converter.Tests/ConversionTests.cs
@@ -42,8 +42,8 @@ func save(path, resource, flags):
                 ConvertGDScriptNamingStyleToSharp = true
             });
 
-            var treeWalker = new GDTreeWalker(visitor);
-            treeWalker.WalkInNode(declaration);
+           // var treeWalker = new GDTreeWalker(visitor);
+           // treeWalker.WalkInNode(declaration);
 
             var csharpCode = visitor.BuildCSharpNormalisedCode();
 
diff --git a/src/GDShrapt.Converter/CSharpGeneratingVisitor.cs b/src/GDShrapt.Converter/CSharpGeneratingVisitor.cs
index 8facc54..94d470c 100644
--- a/src/GDShrapt.Converter/CSharpGeneratingVisitor.cs
+++ b/src/GDShrapt.Converter/CSharpGeneratingVisitor.cs
@@ -9,7 +9,7 @@
 
 namespace GDShrapt.Converter
 {
-    public class CSharpGeneratingVisitor : INodeVisitor
+    public class CSharpGeneratingVisitor //: INodeVisitor
     {
         private readonly ConversionSettings _settings;
 
@@ -200,7 +200,7 @@ public void Visit(GDBracketExpression e)
         }
 
         /////////////////////////////////////////////////////////////////////////////////////////////////
-        public void Visit(GDCallExression e)
+        public void Visit(GDCallExpression e)
         {
 
         }
diff --git a/src/GDShrapt.Converter/Program.cs b/src/GDShrapt.Converter/Program.cs
index 108b813..370b3b9 100644
--- a/src/GDShrapt.Converter/Program.cs
+++ b/src/GDShrapt.Converter/Program.cs
@@ -55,8 +55,8 @@ static void ParseFile(GDScriptReader parser, string filePath, string destination
                     ConvertGDScriptNamingStyleToSharp = true
                 });
 
-                var treeWalker = new GDTreeWalker(visitor);
-                treeWalker.WalkInNode(declaration);
+                //var treeWalker = new GDTreeWalker(visitor);
+                //treeWalker.WalkInNode(declaration);
 
                 // Generate C# code and save it in a file
                 var newPath = Path.ChangeExtension(destinationPath, ".cs");
diff --git a/src/GDShrapt.Reader.Tests/ParsingTests.cs b/src/GDShrapt.Reader.Tests/ParsingTests.cs
index 92ac887..41c9f95 100644
--- a/src/GDShrapt.Reader.Tests/ParsingTests.cs
+++ b/src/GDShrapt.Reader.Tests/ParsingTests.cs
@@ -346,7 +346,7 @@ public void ForStatementTest2()
             var forStatement = (GDForStatement)statement;
 
             Assert.AreEqual("i", forStatement.Variable?.Sequence);
-            Assert.IsInstanceOfType(forStatement.Collection, typeof(GDCallExression));
+            Assert.IsInstanceOfType(forStatement.Collection, typeof(GDCallExpression));
             Assert.AreEqual("range(2, 8, 2)", forStatement.Collection.ToString());
 
             Assert.AreEqual(1, forStatement.Statements.Count);
@@ -1348,7 +1348,7 @@ public void MethodsChainTest()
 
             Assert.AreEqual(GDDualOperatorType.Addition, dualOperator.OperatorType);
 
-            Assert.IsInstanceOfType(dualOperator.LeftExpression, typeof(GDCallExression));
+            Assert.IsInstanceOfType(dualOperator.LeftExpression, typeof(GDCallExpression));
             Assert.IsInstanceOfType(dualOperator.RightExpression, typeof(GDDualOperatorExression));
 
             var rightDualOperator = (GDDualOperatorExression)dualOperator.RightExpression;
@@ -1356,30 +1356,30 @@ public void MethodsChainTest()
             Assert.AreEqual(GDDualOperatorType.Division, rightDualOperator.OperatorType);
             Assert.AreEqual("D()", rightDualOperator.LeftExpression.ToString());
 
-            Assert.IsInstanceOfType(rightDualOperator.RightExpression, typeof(GDCallExression));
+            Assert.IsInstanceOfType(rightDualOperator.RightExpression, typeof(GDCallExpression));
 
-            var rightCallExpression = (GDCallExression)rightDualOperator.RightExpression;
+            var rightCallExpression = (GDCallExpression)rightDualOperator.RightExpression;
 
             Assert.AreEqual("E()(\"test\")", rightCallExpression.ToString());
 
-            var callExpression = (GDCallExression)dualOperator.LeftExpression;
+            var callExpression = (GDCallExpression)dualOperator.LeftExpression;
             Assert.AreEqual(0, callExpression.Parameters.Count);
             var memberOperatorExpression = callExpression.CallerExpression.CastOrAssert<GDMemberOperatorExpression>();
             Assert.AreEqual("C", memberOperatorExpression.Identifier?.Sequence);
 
-            callExpression = memberOperatorExpression.CallerExpression.CastOrAssert<GDCallExression>();
+            callExpression = memberOperatorExpression.CallerExpression.CastOrAssert<GDCallExpression>();
             Assert.AreEqual(0, callExpression.Parameters.Count);
             memberOperatorExpression = callExpression.CallerExpression.CastOrAssert<GDMemberOperatorExpression>();
             Assert.AreEqual("B", memberOperatorExpression.Identifier?.Sequence);
 
-            callExpression = memberOperatorExpression.CallerExpression.CastOrAssert<GDCallExression>();
+            callExpression = memberOperatorExpression.CallerExpression.CastOrAssert<GDCallExpression>();
             Assert.AreEqual(1, callExpression.Parameters.Count);
             Assert.AreEqual("-3", callExpression.Parameters.ToString());
 
-            callExpression = callExpression.CallerExpression.CastOrAssert<GDCallExression>();
+            callExpression = callExpression.CallerExpression.CastOrAssert<GDCallExpression>();
             Assert.AreEqual(0, callExpression.Parameters.Count);
 
-            callExpression = callExpression.CallerExpression.CastOrAssert<GDCallExression>();
+            callExpression = callExpression.CallerExpression.CastOrAssert<GDCallExpression>();
             Assert.AreEqual(1, callExpression.Parameters.Count);
             Assert.AreEqual("1 + 2", callExpression.Parameters.ToString());
 
@@ -1428,7 +1428,7 @@ public void BaseMethodCallTest()
 
             Assert.IsInstanceOfType(callStatement.Tokens.Last(), typeof(GDSemiColon));
 
-            var callExpression = callStatement.Expression.CastOrAssert<GDCallExression>();
+            var callExpression = callStatement.Expression.CastOrAssert<GDCallExpression>();
 
             Assert.AreEqual("._init", callExpression.CallerExpression.ToString());
             Assert.AreEqual("\"1234\"", callExpression.Parameters.ToString());
@@ -1468,7 +1468,7 @@ public void GetNodeTest()
 
             Assert.IsNotNull(expression);
 
-            var call = expression.CastOrAssert<GDCallExression>();
+            var call = expression.CastOrAssert<GDCallExpression>();
 
             var memberOperator = call.CallerExpression.CastOrAssert<GDMemberOperatorExpression>();
             Assert.AreEqual("CallMethod", memberOperator.Identifier.Sequence);
@@ -1488,7 +1488,7 @@ public void NodePathTest()
 
             var expression = reader.ParseExpression(code);
 
-            var call = expression.CastOrAssert<GDCallExression>();
+            var call = expression.CastOrAssert<GDCallExpression>();
             Assert.AreEqual("0", call.Parameters.ToString());
 
             var memberOperator = call.CallerExpression.CastOrAssert<GDMemberOperatorExpression>();
diff --git a/src/GDShrapt.Reader.Tests/SyntaxTests.cs b/src/GDShrapt.Reader.Tests/SyntaxTests.cs
index 63d0c2d..94e2891 100644
--- a/src/GDShrapt.Reader.Tests/SyntaxTests.cs
+++ b/src/GDShrapt.Reader.Tests/SyntaxTests.cs
@@ -137,5 +137,46 @@ public void DictionaryCodeStyleTest()
             Assert.AreEqual(2, expression.AllTokens.OfType<GDComment>().Count());
             AssertHelper.CompareCodeStrings(code, "\n"+expression.ToString());
         }
+
+        [TestMethod]
+        public void SyntaxCloneTest()
+        {
+            var reader = new GDScriptReader();
+
+            var code = @"
+# before tool comment
+tool # tool comment
+
+# before class name comment
+class_name HTerrainDataSaver # class name comment
+
+# before extends comment
+extends ResourceFormatSaver # extends comment
+
+# before const comment
+const HTerrainData = preload(""./ hterrain_data.gd"") # const comment
+
+# before func comment 1
+# before func comment 2
+func get_recognized_extensions(res): # func comment
+
+    # before if statement comment
+	if res != null and res is HTerrainData: # if expression comment
+# before return statement comment
+		return PoolStringArray([HTerrainData.META_EXTENSION]) # if true statement comment
+
+	return PoolStringArray()
+
+# end file comment 1
+# end file comment 2
+";
+
+            var @class = reader.ParseFileContent(code);
+
+            Assert.IsNotNull(@class);
+
+            var clone = @class.Clone();
+            AssertHelper.CompareCodeStrings(@class.ToString(), clone.ToString());
+        }
     }
 }
diff --git a/src/GDShrapt.Reader/Atributes/GDClassNameAtribute.cs b/src/GDShrapt.Reader/Atributes/GDClassNameAtribute.cs
index ed29b87..39d5f6c 100644
--- a/src/GDShrapt.Reader/Atributes/GDClassNameAtribute.cs
+++ b/src/GDShrapt.Reader/Atributes/GDClassNameAtribute.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDClassNameAtribute : GDClassAtribute,
+    public sealed class GDClassNameAtribute : GDClassAtribute,
         IKeywordReceiver<GDClassNameKeyword>,
         IIdentifierReceiver,
         ITokenReceiver<GDComma>,
diff --git a/src/GDShrapt.Reader/Atributes/GDExtendsAtribute.cs b/src/GDShrapt.Reader/Atributes/GDExtendsAtribute.cs
index 80b514d..e189ef8 100644
--- a/src/GDShrapt.Reader/Atributes/GDExtendsAtribute.cs
+++ b/src/GDShrapt.Reader/Atributes/GDExtendsAtribute.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDExtendsAtribute : GDClassAtribute,
+    public sealed class GDExtendsAtribute : GDClassAtribute,
         IKeywordReceiver<GDExtendsKeyword>,
         ITypeReceiver,
         IStringReceiver
diff --git a/src/GDShrapt.Reader/Atributes/GDToolAtribute.cs b/src/GDShrapt.Reader/Atributes/GDToolAtribute.cs
index fd1b78b..f719499 100644
--- a/src/GDShrapt.Reader/Atributes/GDToolAtribute.cs
+++ b/src/GDShrapt.Reader/Atributes/GDToolAtribute.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDToolAtribute : GDClassAtribute, IKeywordReceiver<GDToolKeyword>
+    public sealed class GDToolAtribute : GDClassAtribute, IKeywordReceiver<GDToolKeyword>
     {
         internal GDToolKeyword ToolKeyword
         {
diff --git a/src/GDShrapt.Reader/Basics/GDNode.cs b/src/GDShrapt.Reader/Basics/GDNode.cs
index 09ffec0..9e61173 100644
--- a/src/GDShrapt.Reader/Basics/GDNode.cs
+++ b/src/GDShrapt.Reader/Basics/GDNode.cs
@@ -73,7 +73,7 @@ public override void AppendTo(StringBuilder builder)
                 token.AppendTo(builder);
         }
 
-        public override string ToString()
+        public sealed override string ToString()
         {
             var builder = new StringBuilder();
             
@@ -92,7 +92,7 @@ public override string ToString()
         public override GDSyntaxToken Clone()
         {
             var node = CreateEmptyInstance();
-            node.Form.CloneFrom(node.Form);
+            node.Form.CloneFrom(Form);
             return node;
         }
 
diff --git a/src/GDShrapt.Reader/GDShrapt.Reader.csproj b/src/GDShrapt.Reader/GDShrapt.Reader.csproj
index d5b7204..0329e7d 100644
--- a/src/GDShrapt.Reader/GDShrapt.Reader.csproj
+++ b/src/GDShrapt.Reader/GDShrapt.Reader.csproj
@@ -3,7 +3,7 @@
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
-    <Version>2.0.0-alpha</Version>
+    <Version>2.1.0-alpha</Version>
     <Authors>elamaunt</Authors>
     <Product>GDShrapt</Product>
     <Description>GDShrapt.Reader is .Net library and object-oriented one-pass parser of GDScript. It can build a lexical tree of GDScript code or generate a new code from scratch.
@@ -16,8 +16,8 @@ Usage: Just create GDScriptReader instance and call methods from it.</Descriptio
     <RepositoryUrl>https://github.com/elamaunt/GDShrapt</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
     <PackageTags>GDShrapt GDScript reader parser codegeneration Godot lexical analyzer</PackageTags>
-    <AssemblyVersion>2.0.0</AssemblyVersion>
-    <FileVersion>2.0.0</FileVersion>
+    <AssemblyVersion>2.1.0</AssemblyVersion>
+    <FileVersion>2.1.0</FileVersion>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
   </PropertyGroup>
 
diff --git a/src/GDShrapt.Reader/GDTokensForm.cs b/src/GDShrapt.Reader/GDTokensForm.cs
index b0df5b9..55135ec 100644
--- a/src/GDShrapt.Reader/GDTokensForm.cs
+++ b/src/GDShrapt.Reader/GDTokensForm.cs
@@ -717,6 +717,30 @@ protected void Set(GDSyntaxToken value, int index)
             node.Value = value;
         }
 
+        /// <summary>
+        /// Used only by cloning methods. <see cref="CloneFrom(GDTokensForm)"/>
+        /// </summary>
+        void SetOrAdd(GDSyntaxToken value, int index)
+        {
+            if (index >= _statePoints.Count)
+            {
+                // Only for ListForms
+                _statePoints.Add(_list.AddLast(value));
+
+                if (value != null)
+                    value.Parent = _owner;
+            }
+            else
+            {
+                var node = _statePoints[index];
+
+                if (value != null)
+                    value.Parent = _owner;
+
+                node.Value = value;
+            }
+        }
+
         protected T Get<T>(int index) where T : GDSyntaxToken => (T)_statePoints[index].Value;
         protected GDSyntaxToken Get(int index) => _statePoints[index].Value;
 
@@ -814,30 +838,35 @@ internal int CountTokensBetween(int start, int end)
             return counter;
         }
 
+        /// <summary>
+        /// Main nodes cloning method. Current form must be empty
+        /// </summary>
+        /// <param name="form">The form to be cloned</param>
         internal void CloneFrom(GDTokensForm form)
         {
-            if (_initialSize != form._initialSize)
-                throw new InvalidOperationException("Forms must have same size");
+            if ((_initialSize != 0 || form._initialSize != 0) && _initialSize != form._initialSize)
+                throw new InvalidOperationException("Forms must have same size or zero");
 
             if (StateIndex > 0)
                 throw new InvalidOperationException("The form must be at initial state");
 
+            if (form._list.Count == 0)
+                return;
+
             var node = form._list.First;
             var point = form._statePoints[StateIndex];
 
-            while (true)
+            while (node != null)
             {
                 if (point == node)
                 {
-                    Set(point.Value?.Clone(), StateIndex++);
-                    point = form._statePoints[StateIndex];
+                    SetOrAdd(node.Value?.Clone(), StateIndex++);
+                    point = form._statePoints.ElementAtOrDefault(StateIndex);
                 }
                 else
                 {
-                    var clone = point.Value?.Clone();
-
-                    if (clone != null)
-                        AddBeforeActiveToken(clone);
+                    var clone = node.Value?.Clone();
+                    AddBeforeActiveToken(clone);
                 }
 
                 node = node.Next;
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDComment.cs b/src/GDShrapt.Reader/SimpleTokens/GDComment.cs
index 3974575..b05666a 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDComment.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDComment.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDComment : GDCharSequence
+    public sealed class GDComment : GDCharSequence
     {
         public GDComment()
         {
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDCornerCloseBracket.cs b/src/GDShrapt.Reader/SimpleTokens/GDCornerCloseBracket.cs
index c6dad00..3fcadd6 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDCornerCloseBracket.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDCornerCloseBracket.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDCornerCloseBracket : GDSingleCharToken, IGDStructureToken
+    public sealed class GDCornerCloseBracket : GDSingleCharToken, IGDStructureToken
     {
         public override char Char => '>';
 
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDCornerOpenBracket.cs b/src/GDShrapt.Reader/SimpleTokens/GDCornerOpenBracket.cs
index 0e5e49f..c3b3891 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDCornerOpenBracket.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDCornerOpenBracket.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDCornerOpenBracket : GDSingleCharToken, IGDStructureToken
+    public sealed class GDCornerOpenBracket : GDSingleCharToken, IGDStructureToken
     {
         public override char Char => '<';
 
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDFigureCloseBracket.cs b/src/GDShrapt.Reader/SimpleTokens/GDFigureCloseBracket.cs
index 8491313..77be662 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDFigureCloseBracket.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDFigureCloseBracket.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDFigureCloseBracket : GDSingleCharToken, IGDStructureToken
+    public sealed class GDFigureCloseBracket : GDSingleCharToken, IGDStructureToken
     {
         public override char Char => '}';
 
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDFigureOpenBracket.cs b/src/GDShrapt.Reader/SimpleTokens/GDFigureOpenBracket.cs
index b5c1554..ae4e2a4 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDFigureOpenBracket.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDFigureOpenBracket.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDFigureOpenBracket : GDSingleCharToken, IGDStructureToken
+    public sealed class GDFigureOpenBracket : GDSingleCharToken, IGDStructureToken
     {
         public override char Char => '{';
 
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDIdentifier.cs b/src/GDShrapt.Reader/SimpleTokens/GDIdentifier.cs
index 2105e4c..0947dc8 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDIdentifier.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDIdentifier.cs
@@ -3,7 +3,7 @@
 
 namespace GDShrapt.Reader
 {
-    public class GDIdentifier : GDDataToken
+    public sealed class GDIdentifier : GDDataToken
     {
         public bool IsPi => string.Equals(Sequence, "PI", StringComparison.Ordinal);
         public bool IsTau => string.Equals(Sequence, "TAU", StringComparison.Ordinal);
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDIntendation.cs b/src/GDShrapt.Reader/SimpleTokens/GDIntendation.cs
index ee7e9fc..36401b5 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDIntendation.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDIntendation.cs
@@ -2,7 +2,7 @@
 
 namespace GDShrapt.Reader
 {
-    public class GDIntendation : GDSimpleSyntaxToken
+    public sealed class GDIntendation : GDSimpleSyntaxToken
     {
         int _lineIntendation;
         int _spaceCounter;
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDNumber.cs b/src/GDShrapt.Reader/SimpleTokens/GDNumber.cs
index f929e75..fedc0d8 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDNumber.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDNumber.cs
@@ -4,7 +4,7 @@
 
 namespace GDShrapt.Reader
 {
-    public class GDNumber : GDLiteralToken
+    public sealed class GDNumber : GDLiteralToken
     {
         readonly StringBuilder _stringBuilder = new StringBuilder();
 
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDSpace.cs b/src/GDShrapt.Reader/SimpleTokens/GDSpace.cs
index 75c60ad..04331f6 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDSpace.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDSpace.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDSpace : GDCharSequence
+    public sealed class GDSpace : GDCharSequence
     {
         internal override bool CanAppendChar(char c, GDReadingState state)
         {
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDSquareCloseBracket.cs b/src/GDShrapt.Reader/SimpleTokens/GDSquareCloseBracket.cs
index 58121b6..2c91949 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDSquareCloseBracket.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDSquareCloseBracket.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDSquareCloseBracket : GDSingleCharToken, IGDStructureToken
+    public sealed class GDSquareCloseBracket : GDSingleCharToken, IGDStructureToken
     {
         public override char Char => ']';
 
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDSquareOpenBracket.cs b/src/GDShrapt.Reader/SimpleTokens/GDSquareOpenBracket.cs
index d9e821a..6f93d72 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDSquareOpenBracket.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDSquareOpenBracket.cs
@@ -1,6 +1,6 @@
 namespace GDShrapt.Reader
 {
-    public class GDSquareOpenBracket : GDSingleCharToken, IGDStructureToken
+    public sealed class GDSquareOpenBracket : GDSingleCharToken, IGDStructureToken
     {
         public override char Char => '[';
 
diff --git a/src/GDShrapt.Reader/SimpleTokens/GDType.cs b/src/GDShrapt.Reader/SimpleTokens/GDType.cs
index e28b376..4b6d8e2 100644
--- a/src/GDShrapt.Reader/SimpleTokens/GDType.cs
+++ b/src/GDShrapt.Reader/SimpleTokens/GDType.cs
@@ -3,7 +3,7 @@
 
 namespace GDShrapt.Reader
 {
-    public class GDType : GDDataToken
+    public sealed class GDType : GDDataToken
     {
         public bool ExtractTypeFromInitializer => IsEmpty;
         public bool IsEmpty => Sequence.IsNullOrEmpty();