code: func (c *CAClientImpl) Register(request *api.RegistrationRequest) (string, error) {
  	if c.adapter == nil {
  		return "", fmt.Errorf("no CAs configured for organization: %s", c.orgName)
  	}
  	if c.registrar.EnrollID == "" {
  		return "", api.ErrCARegistrarNotFound
  	}
  	// Validate registration request
  	if request == nil {
  		return "", errors.New("registration request is required")
  	}
  	if request.Name == "" {
  		return "", errors.New("request.Name is required")
  	}
  
  	registrar, err := c.getRegistrar(c.registrar.EnrollID, c.registrar.EnrollSecret)
  	if err != nil {
  		return "", err
  	}
  
  	secret, err := c.adapter.Register(registrar.PrivateKey(), registrar.EnrollmentCertificate(), request)
  	if err != nil {
  		return "", errors.Wrap(err, "failed to register user")
  	}
  
  	return secret, nil
  }
docs: // Register a User with the Fabric CA
  // request: Registration Request
  // Returns Enrolment Secret