code: def run(self):
          
  
          self._systemd_notify_once()
          self._child_supervisor = _utils.spawn(self._child_supervisor_thread)
          self._wait_forever()
docs: Start and supervise services workers
  
          This method will start and supervise all children processes
          until the master process asked to shutdown by a SIGTERM.
  
          All spawned processes are part of the same unix process group.