code: def create_subtask(self, cor, name=None, stop_timeout=1.0):
          
  
          if self.stopped:
              raise InternalError("Cannot add a subtask to a parent that is already stopped")
  
          subtask = BackgroundTask(cor, name, loop=self._loop, stop_timeout=stop_timeout)
          self.add_subtask(subtask)
          return subtask
docs: Create and add a subtask from a coroutine.
  
          This function will create a BackgroundTask and then
          call self.add_subtask() on it.
  
          Args:
              cor (coroutine): The coroutine that should be wrapped
                  in a background task.
              name (str): An optional name for the task.
              stop_timeout (float): The maximum time to wait for this
                  subtask to die after stopping it.
  
          Returns:
              Backgroundtask: The created subtask.