code: def unpublish_view(self, request, object_id):
          
          kwargs = {'model_admin': self, 'object_id': object_id}
          view_class = self.unpublish_view_class
          return view_class.as_view(**kwargs)(request)
docs: Instantiates a class-based view that redirects to Wagtail's 'unpublish'
          view for models that extend 'Page' (if the user has sufficient
          permissions). We do this via our own view so that we can reliably
          control redirection of the user back to the index_view once the action
          is completed. The view class used can be overridden by changing the
          'unpublish_view_class' attribute.