code: func NewDefaultUAAManager(sysDomain, clientID, clientSecret, userAgent string, peek bool) (Manager, error) {
  	target := fmt.Sprintf("https://uaa.%s", sysDomain)
  	client, err := uaaclient.NewWithClientCredentials(target, "", clientID, clientSecret, uaaclient.OpaqueToken, true)
  	if err != nil {
  		return nil, err
  	}
  
  	client.UserAgent = userAgent
  	return &DefaultUAAManager{
  		Client: client,
  		Peek:   peek,
  	}, nil
  }
docs: //NewDefaultUAAManager -