private ArgumentListSyntax ParseParenthesizedArgumentList(bool atLeastOneArg)
{
SyntaxToken leftParenToken, rightParenToken;
SeparatedSyntaxList<ExpressionSyntax> arguments;
ParseArgumentList(SyntaxKind.OpenParenToken, SyntaxKind.CloseParenToken, atLeastOneArg, out leftParenToken, out arguments, out rightParenToken);
return new ArgumentListSyntax(leftParenToken, arguments, rightParenToken);
}