docs: def getTargetNamespace(self):
          """return targetNamespace
          """
          parent = self
          targetNamespace = 'targetNamespace'
          tns = self.attributes.get(targetNamespace)
          while not tns and parent and parent._parent is not None:
              parent = parent._parent()
              tns = parent.attributes.get(targetNamespace)
          return tns or ''