public virtual void VisitNamespace(NamespaceDeclaration namespaceDeclaration)
 {
     VisitCollection(namespaceDeclaration.Namespaces);
     VisitCollection(namespaceDeclaration.Types);
     VisitCollection(namespaceDeclaration.Usings);
 }
 public static NamespaceDeclaration AddNamespace(this INamespaceDeclarationContainer unit, NamespaceDeclaration ns)
 {
     unit.Namespaces.Add(ns);
     return(ns);
 }