C# 如何覆盖VisualStudio？

我正试图在VisualStudio扩展中实现我自己版本的brace completion，因为我需要能够在它发生时进行过滤

[Export(typeof(IBraceCompletionContextProvider))]
public class CollabBrace : IBraceCompletionContextProvider {
    public bool TryCreateContext(ITextView textView, SnapshotPoint openingPoint, char openingBrace, char closingBrace, out IBraceCompletionContext context) {
        throw new NotImplementedException();
    }
}

[Export(typeof(IBraceCompletionSessionProvider))]
[ContentType("text")]
[BracePair('{', '}')]
[BracePair('[', ']')]
public class CollabBrace2 : IBraceCompletionSessionProvider {
    public bool TryCreateSession(ITextView textView, SnapshotPoint openingPoint, char openingBrace, char closingBrace, out IBraceCompletionSession session) {
        throw new NotImplementedException();
    }
}

这里有两种方法，我试着获得支撑完成的上下文和会话，但它们从未触发

任何例子或帮助都将不胜感激