private static async Task <Document> SimplifyLambdaExpressionParameterListAsync( Document document, ParenthesizedLambdaExpressionSyntax lambda, CancellationToken cancellationToken) { SyntaxNode oldRoot = await document.GetSyntaxRootAsync(cancellationToken); LambdaExpressionSyntax newLambda = SimplifyLambdaExpressionParameterListSyntaxRewriter.VisitNode(lambda); if (lambda.ParameterList.Parameters.Count == 1) { newLambda = ConvertParenthesizedLambdaToSimpleLambda((ParenthesizedLambdaExpressionSyntax)newLambda); } newLambda = newLambda.WithAdditionalAnnotations(Formatter.Annotation); SyntaxNode newRoot = oldRoot.ReplaceNode(lambda, newLambda); return(document.WithSyntaxRoot(newRoot)); }