code: def add_user_to_group(self, username, groupname, raise_on_error=False):
          
          data = {
                  'name': groupname,
          }
          response = self._post(self.rest_url + "/user/group/direct",
                                params={"username": username,},
                                data=json.dumps(data))
  
          if response.status_code == 201:
              return True
  
          if raise_on_error:
              raise RuntimeError(response.json()['message'])
  
          return False
docs: Add a user to a group
          :param username: The username to assign to the group
          :param groupname: The group name into which to assign the user
          :return: True on success, False on failure.