Made SetCapability virtual instead of abstract

src/Protocol/Document/Server/ICodeActionHandler.cs

@@ -23,7 +23,8 @@ public CodeActionHandler(CodeActionRegistrationOptions registrationOptions)
 
         public CodeActionRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<CommandOrCodeActionContainer> Handle(CodeActionParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(CodeActionCapability capability);
+        public virtual void SetCapability(CodeActionCapability capability) => Capability = capability;
+        protected CodeActionCapability Capability { get; private set; }
     }
 
     public static class CodeActionHandlerExtensions

src/Protocol/Document/Server/ICodeLensHandler.cs

@@ -18,6 +18,7 @@ public interface ICodeLensResolveHandler : ICanBeResolvedHandler<CodeLens> { }
     public abstract class CodeLensHandler : ICodeLensHandler, ICodeLensResolveHandler
     {
         private readonly CodeLensRegistrationOptions _options;
+
         public CodeLensHandler(CodeLensRegistrationOptions registrationOptions)
         {
             _options = registrationOptions;
@@ -27,7 +28,8 @@ public CodeLensHandler(CodeLensRegistrationOptions registrationOptions)
         public abstract Task<CodeLensContainer> Handle(CodeLensParams request, CancellationToken cancellationToken);
         public abstract Task<CodeLens> Handle(CodeLens request, CancellationToken cancellationToken);
         public abstract bool CanResolve(CodeLens value);
-        public abstract void SetCapability(CodeLensCapability capability);
+        public virtual void SetCapability(CodeLensCapability capability) => Capability = capability;
+        protected CodeLensCapability Capability { get; private set; }
     }
 
     public static class CodeLensHandlerExtensions

src/Protocol/Document/Server/IColorPresentationHandler.cs

@@ -24,7 +24,8 @@ public ColorPresentationHandler(DocumentColorRegistrationOptions registrationOpt
 
         public DocumentColorRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Container<ColorPresentation>> Handle(ColorPresentationParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(ColorProviderCapability capability);
+        public virtual void SetCapability(ColorProviderCapability capability) => Capability = capability;
+        protected ColorProviderCapability Capability { get; private set; }
     }
 
     public static class ColorPresentationHandlerExtensions

src/Protocol/Document/Server/ICompletionHandler.cs

@@ -17,7 +17,8 @@ public interface ICompletionResolveHandler : ICanBeResolvedHandler<CompletionIte
 
     public abstract class CompletionHandler : ICompletionHandler, ICompletionResolveHandler
     {
-        private readonly CompletionRegistrationOptions _options;
+        protected readonly CompletionRegistrationOptions _options;
+
         public CompletionHandler(CompletionRegistrationOptions registrationOptions)
         {
             _options = registrationOptions;
@@ -27,7 +28,8 @@ public CompletionHandler(CompletionRegistrationOptions registrationOptions)
         public abstract Task<CompletionList> Handle(CompletionParams request, CancellationToken cancellationToken);
         public abstract Task<CompletionItem> Handle(CompletionItem request, CancellationToken cancellationToken);
         public abstract bool CanResolve(CompletionItem value);
-        public abstract void SetCapability(CompletionCapability capability);
+        public virtual void SetCapability(CompletionCapability capability) => Capability = capability;
+        protected CompletionCapability Capability { get; private set; }
     }
 
     public static class CompletionHandlerExtensions

src/Protocol/Document/Server/IDeclarationHandler.cs

@@ -22,7 +22,8 @@ public DeclarationHandler(TextDocumentRegistrationOptions registrationOptions)
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<LocationOrLocationLinks> Handle(DeclarationParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(DeclarationCapability capability);
+        public virtual void SetCapability(DeclarationCapability capability) => Capability = capability;
+        protected DeclarationCapability Capability { get; private set; }
     }
 
     public static class DeclarationHandlerExtensions

src/Protocol/Document/Server/IDefinitionHandler.cs

@@ -22,7 +22,8 @@ public DefinitionHandler(TextDocumentRegistrationOptions registrationOptions)
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<LocationOrLocationLinks> Handle(DefinitionParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(DefinitionCapability capability);
+        public virtual void SetCapability(DefinitionCapability capability) => Capability = capability;
+        protected DefinitionCapability Capability { get; private set; }
     }
 
     public static class DefinitionHandlerExtensions

src/Protocol/Document/Server/IDidChangeTextDocumentHandler.cs

@@ -26,7 +26,8 @@ public DidChangeTextDocumentHandler(TextDocumentChangeRegistrationOptions regist
 
         public TextDocumentChangeRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Unit> Handle(DidChangeTextDocumentParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(SynchronizationCapability capability);
+        public virtual void SetCapability(SynchronizationCapability capability) => Capability = capability;
+        protected SynchronizationCapability Capability { get; private set; }
     }
 
     public static class DidChangeTextDocumentHandlerExtensions

src/Protocol/Document/Server/IDidCloseTextDocumentHandler.cs

@@ -23,7 +23,8 @@ public DidCloseTextDocumentHandler(TextDocumentRegistrationOptions registrationO
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Unit> Handle(DidCloseTextDocumentParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(SynchronizationCapability capability);
+        public virtual void SetCapability(SynchronizationCapability capability) => Capability = capability;
+        protected SynchronizationCapability Capability { get; private set; }
     }
 
     public static class DidCloseTextDocumentHandlerExtensions

src/Protocol/Document/Server/IDidOpenTextDocumentHandler.cs

@@ -23,7 +23,8 @@ public DidOpenTextDocumentHandler(TextDocumentRegistrationOptions registrationOp
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Unit> Handle(DidOpenTextDocumentParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(SynchronizationCapability capability);
+        public virtual void SetCapability(SynchronizationCapability capability) => Capability = capability;
+        protected SynchronizationCapability Capability { get; private set; }
     }
 
     public static class DidOpenTextDocumentHandlerExtensions

src/Protocol/Document/Server/IDidSaveTextDocumentHandler.cs

@@ -23,7 +23,8 @@ public DidSaveTextDocumentHandler(TextDocumentSaveRegistrationOptions registrati
 
         public TextDocumentSaveRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Unit> Handle(DidSaveTextDocumentParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(SynchronizationCapability capability);
+        public virtual void SetCapability(SynchronizationCapability capability) => Capability = capability;
+        protected SynchronizationCapability Capability { get; private set; }
     }
 
     public static class DidSaveTextDocumentHandlerExtensions

src/Protocol/Document/Server/IDocumentColorHandler.cs

@@ -22,7 +22,8 @@ public DocumentColorHandler(DocumentColorRegistrationOptions registrationOptions
 
         public DocumentColorRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Container<ColorInformation>> Handle(DocumentColorParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(ColorProviderCapability capability);
+        public virtual void SetCapability(ColorProviderCapability capability) => Capability = capability;
+        protected ColorProviderCapability Capability { get; private set; }
     }
 
     public static class DocumentColorHandlerExtensions

src/Protocol/Document/Server/IDocumentFormattingHandler.cs

@@ -22,7 +22,8 @@ public DocumentFormattingHandler(TextDocumentRegistrationOptions registrationOpt
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<TextEditContainer> Handle(DocumentFormattingParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(DocumentFormattingCapability capability);
+        public virtual void SetCapability(DocumentFormattingCapability capability) => Capability = capability;
+        protected DocumentFormattingCapability Capability { get; private set; }
     }
 
     public static class DocumentFormattingHandlerExtensions

src/Protocol/Document/Server/IDocumentHighlightHandler.cs

@@ -22,7 +22,8 @@ public DocumentHighlightHandler(TextDocumentRegistrationOptions registrationOpti
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<DocumentHighlightContainer> Handle(DocumentHighlightParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(DocumentHighlightCapability capability);
+        public virtual void SetCapability(DocumentHighlightCapability capability) => Capability = capability;
+        protected DocumentHighlightCapability Capability { get; private set; }
     }
 
     public static class DocumentHighlightHandlerExtensions

src/Protocol/Document/Server/IDocumentLinkHandler.cs

@@ -18,6 +18,7 @@ public interface IDocumentLinkResolveHandler : ICanBeResolvedHandler<DocumentLin
     public abstract class DocumentLinkHandler : IDocumentLinkHandler, IDocumentLinkResolveHandler
     {
         private readonly DocumentLinkRegistrationOptions _options;
+
         public DocumentLinkHandler(DocumentLinkRegistrationOptions registrationOptions)
         {
             _options = registrationOptions;
@@ -27,7 +28,8 @@ public DocumentLinkHandler(DocumentLinkRegistrationOptions registrationOptions)
         public abstract Task<DocumentLinkContainer> Handle(DocumentLinkParams request, CancellationToken cancellationToken);
         public abstract Task<DocumentLink> Handle(DocumentLink request, CancellationToken cancellationToken);
         public abstract bool CanResolve(DocumentLink value);
-        public abstract void SetCapability(DocumentLinkCapability capability);
+        public virtual void SetCapability(DocumentLinkCapability capability) => Capability = capability;
+        protected DocumentLinkCapability Capability { get; private set; }
     }
 
     public static class DocumentLinkHandlerExtensions

src/Protocol/Document/Server/IDocumentOnTypeFormatHandler.cs

@@ -22,7 +22,8 @@ public DocumentOnTypeFormatHandler(DocumentOnTypeFormattingRegistrationOptions r
 
         public DocumentOnTypeFormattingRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<TextEditContainer> Handle(DocumentOnTypeFormattingParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(DocumentOnTypeFormattingCapability capability);
+        public virtual void SetCapability(DocumentOnTypeFormattingCapability capability) => Capability = capability;
+        protected DocumentOnTypeFormattingCapability Capability { get; private set; }
     }
 
     public static class DocumentOnTypeFormatHandlerExtensions

src/Protocol/Document/Server/IDocumentRangeFormattingHandler.cs

@@ -22,7 +22,8 @@ public DocumentRangeFormattingHandler(TextDocumentRegistrationOptions registrati
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<TextEditContainer> Handle(DocumentRangeFormattingParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(DocumentRangeFormattingCapability capability);
+        public virtual void SetCapability(DocumentRangeFormattingCapability capability) => Capability = capability;
+        protected DocumentRangeFormattingCapability Capability { get; private set; }
     }
 
     public static class DocumentRangeFormattingHandlerExtensions

src/Protocol/Document/Server/IDocumentSymbolHandler.cs

@@ -22,7 +22,8 @@ public DocumentSymbolHandler(TextDocumentRegistrationOptions registrationOptions
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<SymbolInformationOrDocumentSymbolContainer> Handle(DocumentSymbolParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(DocumentSymbolCapability capability);
+        public virtual void SetCapability(DocumentSymbolCapability capability) => Capability = capability;
+        protected DocumentSymbolCapability Capability { get; private set; }
     }
 
     public static class DocumentSymbolHandlerExtensions

src/Protocol/Document/Server/IFoldingRangeHandler.cs

@@ -22,7 +22,8 @@ public FoldingRangeHandler(TextDocumentRegistrationOptions registrationOptions)
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Container<FoldingRange>> Handle(FoldingRangeRequestParam request, CancellationToken cancellationToken);
-        public abstract void SetCapability(FoldingRangeCapability capability);
+        public virtual void SetCapability(FoldingRangeCapability capability) => Capability = capability;
+        protected FoldingRangeCapability Capability { get; private set; }
     }
 
     public static class FoldingRangeHandlerExtensions

src/Protocol/Document/Server/IHoverHandler.cs

@@ -22,7 +22,8 @@ public HoverHandler(TextDocumentRegistrationOptions registrationOptions)
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Hover> Handle(HoverParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(HoverCapability capability);
+        public virtual void SetCapability(HoverCapability capability) => Capability = capability;
+        protected HoverCapability Capability { get; private set; }
     }
 
     public static class HoverHandlerExtensions

src/Protocol/Document/Server/IImplementationHandler.cs

@@ -22,7 +22,8 @@ public ImplementationHandler(TextDocumentRegistrationOptions registrationOptions
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<LocationOrLocationLinks> Handle(ImplementationParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(ImplementationCapability capability);
+        public virtual void SetCapability(ImplementationCapability capability) => Capability = capability;
+        protected ImplementationCapability Capability { get; private set; }
     }
 
     public static class ImplementationHandlerExtensions

src/Protocol/Document/Server/IPrepareRenameHandler.cs

@@ -22,7 +22,8 @@ public PrepareRenameHandler(TextDocumentRegistrationOptions registrationOptions)
 
         public object GetRegistrationOptions() => new object();
         public abstract Task<RangeOrPlaceholderRange> Handle(PrepareRenameParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(RenameCapability capability);
+        public virtual void SetCapability(RenameCapability capability) => Capability = capability;
+        protected RenameCapability Capability { get; private set; }
     }
 
     public static class PrepareRenameHandlerExtensions

src/Protocol/Document/Server/IReferencesHandler.cs

@@ -22,7 +22,8 @@ public ReferencesHandler(TextDocumentRegistrationOptions registrationOptions)
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<LocationContainer> Handle(ReferenceParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(ReferencesCapability capability);
+        public virtual void SetCapability(ReferencesCapability capability) => Capability = capability;
+        protected ReferencesCapability Capability { get; private set; }
     }
 
     public static class ReferencesHandlerExtensions

src/Protocol/Document/Server/IRenameHandler.cs

@@ -22,7 +22,8 @@ public RenameHandler(RenameRegistrationOptions registrationOptions)
 
         public RenameRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<WorkspaceEdit> Handle(RenameParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(RenameCapability capability);
+        public virtual void SetCapability(RenameCapability capability) => Capability = capability;
+        protected RenameCapability Capability { get; private set; }
     }
 
     public static class RenameHandlerExtensions

src/Protocol/Document/Server/ISignatureHelpHandler.cs

@@ -22,7 +22,8 @@ public SignatureHelpHandler(SignatureHelpRegistrationOptions registrationOptions
 
         public SignatureHelpRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<SignatureHelp> Handle(SignatureHelpParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(SignatureHelpCapability capability);
+        public virtual void SetCapability(SignatureHelpCapability capability) => Capability = capability;
+        protected SignatureHelpCapability Capability { get; private set; }
     }
 
     public static class SignatureHelpHandlerExtensions

src/Protocol/Document/Server/ITextDocumentSyncHandler.cs

@@ -37,7 +37,8 @@ public TextDocumentSyncHandler(TextDocumentSyncKind kind, TextDocumentSaveRegist
         public abstract Task<Unit> Handle(DidChangeTextDocumentParams request, CancellationToken cancellationToken);
         public abstract Task<Unit> Handle(DidSaveTextDocumentParams request, CancellationToken cancellationToken);
         public abstract Task<Unit> Handle(DidCloseTextDocumentParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(SynchronizationCapability capability);
+        public virtual void SetCapability(SynchronizationCapability capability) => Capability = capability;
+        protected SynchronizationCapability Capability { get; private set; }
     }
 
     public static class TextDocumentSyncHandlerExtensions

src/Protocol/Document/Server/ITypeDefinitionHandler.cs

@@ -22,7 +22,8 @@ public TypeDefinitionHandler(TextDocumentRegistrationOptions registrationOptions
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<LocationOrLocationLinks> Handle(TypeDefinitionParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(TypeDefinitionCapability capability);
+        public virtual void SetCapability(TypeDefinitionCapability capability) => Capability = capability;
+        protected TypeDefinitionCapability Capability { get; private set; }
     }
 
     public static class TypeDefinitionHandlerExtensions

src/Protocol/Document/Server/IWillSaveTextDocumentHandler.cs

@@ -23,7 +23,8 @@ public WillSaveTextDocumentHandler(TextDocumentRegistrationOptions registrationO
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<Unit> Handle(WillSaveTextDocumentParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(SynchronizationCapability capability);
+        public virtual void SetCapability(SynchronizationCapability capability) => Capability = capability;
+        protected SynchronizationCapability Capability { get; private set; }
     }
 
     public static class WillSaveTextDocumentHandlerExtensions

src/Protocol/Document/Server/IWillSaveWaitUntilTextDocumentHandler.cs

@@ -23,7 +23,8 @@ public WillSaveWaitUntilTextDocumentHandler(TextDocumentRegistrationOptions regi
 
         public TextDocumentRegistrationOptions GetRegistrationOptions() => _options;
         public abstract Task<TextEditContainer> Handle(WillSaveWaitUntilTextDocumentParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(SynchronizationCapability capability);
+        public virtual void SetCapability(SynchronizationCapability capability) => Capability = capability;
+        protected SynchronizationCapability Capability { get; private set; }
     }
 
     public static class WillSaveWaitUntilTextDocumentHandlerExtensions

src/Protocol/Workspace/Server/IDidChangeConfigurationHandler.cs

@@ -18,7 +18,8 @@ public abstract class DidChangeConfigurationHandler : IDidChangeConfigurationHan
     {
         public object GetRegistrationOptions() => new object();
         public abstract Task<Unit> Handle(DidChangeConfigurationParams request, CancellationToken cancellationToken);
-        public abstract void SetCapability(DidChangeConfigurationCapability capability);
+        public virtual void SetCapability(DidChangeConfigurationCapability capability) => Capability = capability;
+        protected DidChangeConfigurationCapability Capability { get; private set; }
     }
 
     public static class DidChangeConfigurationHandlerExtensions