protected override string GetDocumentationForSymbol(string documentationMemberID, CultureInfo preferredCulture, CancellationToken cancellationToken = default(CancellationToken))
        {
            var symbol = DocumentationCommentId.GetFirstSymbolForDeclarationId(documentationMemberID, _compilation);

            if (symbol != null)
            {
                return(symbol.GetDocumentationCommentXml(preferredCulture, cancellationToken: cancellationToken));
            }

            return(string.Empty);
        }