code: func (a *Adaptor) Connect() (err error) {
  	a.client = paho.NewClient(a.createClientOptions())
  	if token := a.client.Connect(); token.Wait() && token.Error() != nil {
  		err = multierror.Append(err, token.Error())
  	}
  
  	return
  }
docs: // Connect returns true if connection to mqtt is established