code: func dispatchStopSignal(d dispatchRequest, c *instructions.StopSignalCommand) error {
  
  	_, err := signal.ParseSignal(c.Signal)
  	if err != nil {
  		return errdefs.InvalidParameter(err)
  	}
  	d.state.runConfig.StopSignal = c.Signal
  	return d.builder.commit(d.state, fmt.Sprintf("STOPSIGNAL %v", c.Signal))
  }
docs: // STOPSIGNAL signal
  //
  // Set the signal that will be used to kill the container.