code: def single_shot(self, check_status=True, **kwargs):
          
          self.check_pid_file()
          self.set_spectator_mode(False)
          if check_status: self.check_status()
          from .launcher import PyLauncher
          return PyLauncher(self, **kwargs).single_shot()
docs: Use :class:`PyLauncher` to submits one task.
          kwargs contains the options passed to the launcher.
  
          Return:
              number of tasks submitted.