fix warnings

Gu.Roslyn.AnalyzerExtensions.Tests/Symbols/INamedTypeSymbolExttensionsTests.cs

@@ -75,7 +75,7 @@ INamedTypeSymbol GetTypeSymbol(Type current)
         }
 
 #pragma warning disable CA1812, GURA07 // Avoid uninstantiated internal classes
-        private class Nested
+        private sealed class Nested
 #pragma warning restore CA1812, GURA07 // Avoid uninstantiated internal classes
         {
         }

Gu.Roslyn.AnalyzerExtensions.Tests/Walkers/ExecutionWalkerTests/LiteralWalker.cs

@@ -1,12 +1,12 @@
-namespace Gu.Roslyn.AnalyzerExtensions.Tests.Walkers.ExecutionWalkerTests
+namespace Gu.Roslyn.AnalyzerExtensions.Tests.Walkers.ExecutionWalkerTests
 {
     using System.Collections.Generic;
     using System.Threading;
     using Microsoft.CodeAnalysis;
     using Microsoft.CodeAnalysis.CSharp;
     using Microsoft.CodeAnalysis.CSharp.Syntax;
 
-    internal class LiteralWalker : ExecutionWalker<LiteralWalker>
+    internal sealed class LiteralWalker : ExecutionWalker<LiteralWalker>
     {
         private readonly List<LiteralExpressionSyntax> literals = new();
 

Gu.Roslyn.AnalyzerExtensions/Pooled/PooledSet{T}.cs

@@ -13,7 +13,7 @@ namespace Gu.Roslyn.AnalyzerExtensions
     /// A <see cref="HashSet{T}"/> for re-use.
     /// </summary>
     /// <typeparam name="T">The type of items in the set.</typeparam>
-    [DebuggerTypeProxy(typeof(PooledSetDebugView<>))]
+    [DebuggerTypeProxy(typeof(PooledSet<>.DebugView))]
     [DebuggerDisplay("Count = {this.Count}, refCount = {this.refCount}")]
     public sealed class PooledSet<T> : IDisposable, IReadOnlyCollection<T>
     {
@@ -158,5 +158,18 @@ private void ThrowIfDisposed()
                 throw new ObjectDisposedException(typeof(PooledSet<T>).FullName);
             }
         }
+
+        private sealed class DebugView
+        {
+            private readonly PooledSet<T> set;
+
+            internal DebugView(PooledSet<T> set)
+            {
+                this.set = set ?? throw new ArgumentNullException(nameof(set));
+            }
+
+            [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
+            internal T[] Items => this.set.ToArray();
+        }
     }
 }

Gu.Roslyn.CodeFixExtensions/TypeDeclarationSyntaxExtensions.cs

@@ -333,7 +333,7 @@ public static TContaining MoveMember<TContaining>(this TContaining containingTyp
             return (TContaining)containingType.WithMembers(containingType.Members.Move(oldIndex, newIndex));
         }
 
-        private class IndentCommentRewriter : CSharpSyntaxRewriter
+        private sealed class IndentCommentRewriter : CSharpSyntaxRewriter
         {
             private readonly string whitespace;
             private int n;