public override Ust VisitArgument(ArgumentSyntax node) { var result = (Expression)VisitAndReturnNullIfError(node.Expression); if (!node.RefKindKeyword.IsKind(SyntaxKind.None)) { InOutModifierLiteral modifierLiteral = new InOutModifierLiteral( node.RefKindKeyword.IsKind(SyntaxKind.OutKeyword) ? InOutModifier.Out : InOutModifier.InOut, node.RefKindKeyword.GetTextSpan()); result = new ArgumentExpression(modifierLiteral, result, node.GetTextSpan()); } return(result); }