code: def del_permission(self, role, name):
          
          if not self.has_permission(role, name):
              return True
          targetGroup = AuthGroup.objects(role=role, creator=self.client).first()
          target = AuthPermission.objects(groups=targetGroup, name=name, creator=self.client).first()
          if not target:
              return True
          target.delete()
          return True
docs: revoke authorization of a group