private Task <Document> AddSummaryCommentAsync(Document document, BaseTypeDeclarationSyntax declaration, CancellationToken c) { var leadingTrivias = declaration.GetLeadingTrivia(); var whitespaceCount = leadingTrivias[leadingTrivias.Count - 1].Span.Length; var newDeclaration = declaration.WithLeadingTrivia( AnalyzerUtil.GetNewLeadingTriviaWithSummary(leadingTrivias, summaryComments, whitespaceCount)); return(AnalyzerUtil.ReplaceNode(declaration, newDeclaration, document)); }