public override UstNode VisitNamespaceDeclaration(NamespaceDeclarationSyntax node)
{
var nameSpan = node.Name.GetTextSpan();
var name = new StringLiteral(node.Name.ToFullString(), nameSpan, FileNode);
var members = node.Members.Select(member => VisitAndReturnNullIfError(member))
.ToArray();
var result = new NamespaceDeclaration(
name, members,
Language.CSharp, node.GetTextSpan(), FileNode
);
return(result);
}