public JavaQuickInfoSource(ITextBuffer textBuffer, JavaQuickInfoSourceProvider provider)
        {
            Contract.Requires<ArgumentNullException>(textBuffer != null, "textBuffer");
            Contract.Requires<ArgumentNullException>(provider != null, "provider");

            _textBuffer = textBuffer;
            _provider = provider;
        }
        public JavaQuickInfoSource(ITextBuffer textBuffer, JavaQuickInfoSourceProvider provider)
        {
            Contract.Requires <ArgumentNullException>(textBuffer != null, "textBuffer");
            Contract.Requires <ArgumentNullException>(provider != null, "provider");

            _textBuffer = textBuffer;
            _provider   = provider;
        }