code: func (actor Actor) GrantOrgManagerByUsername(guid string, username string) (Warnings, error) {
  	var warnings ccv2.Warnings
  	var err error
  
  	if actor.Config.UAAGrantType() != string(uaaconst.GrantTypeClientCredentials) {
  		warnings, err = actor.CloudControllerClient.UpdateOrganizationManagerByUsername(guid, username)
  	} else {
  		warnings, err = actor.CloudControllerClient.UpdateOrganizationManager(guid, username)
  	}
  
  	return Warnings(warnings), err
  }
docs: // GrantOrgManagerByUsername gives the Org Manager role to the provided user.