private BlockSyntax AddReturnStatement(BlockSyntax node)
        {
            var leadingTrivia = node.Statements.Count > 0
                                ? node.Statements[0].GetLeadingWhitespace()
                                : Whitespace(node.GetLeadingWhitespace().ToFullString() + _transformResult.IndentTrivia.ToFullString());

            return(node.AddStatements(GetReturnTaskCompleted().WithLeadingTrivia(TriviaList(leadingTrivia))));
        }