code: func (state *DockerTaskEngineState) RemoveENIAttachment(mac string) {
  	if mac == "" {
  		log.Debug("Cannot remove empty eni attachment information")
  		return
  	}
  	state.lock.Lock()
  	defer state.lock.Unlock()
  
  	if _, ok := state.eniAttachments[mac]; ok {
  		delete(state.eniAttachments, mac)
  	} else {
  		seelog.Debugf("Delete non-existed eni attachment: %v", mac)
  	}
  }
docs: // RemoveENIAttachment removes the eni from state and stop managing