code: def get_placeholder_data_view(self, request, object_id):
          
          language = 'en'  #request.POST['language']
          with translation.override(language):  # Use generic solution here, don't assume django-parler is used now.
              obj = self.get_object(request, object_id)
  
          if obj is None:
              json = {'success': False, 'error': 'Page not found'}
              status = 404
          elif not self.has_change_permission(request, obj):
              json = {'success': False, 'error': 'No access to page'}
              status = 403
          else:
              # Fetch the forms that would be displayed,
              # return the data as serialized form data.
              status = 200
              json = {
                  'success': True,
                  'object_id': object_id,
                  'language_code': language,
                  'formset_forms': self._get_object_formset_data(request, obj),
              }
  
          return JsonResponse(json, status=status)
docs: Return the placeholder data as dictionary.
          This is used in the client for the "copy" functionality.