code: def choose_parent_view(self, request):
          
          kwargs = {'model_admin': self}
          view_class = self.choose_parent_view_class
          return view_class.as_view(**kwargs)(request)
docs: Instantiates a class-based view to provide a view that allows a parent
          page to be chosen for a new object, where the assigned model extends
          Wagtail's Page model, and there is more than one potential parent for
          new instances. The view class used can be overridden by changing the
          'choose_parent_view_class' attribute.