code: func (m *Manager) GetAuthorization(username, organization string) (authorization *Authorization, err error) {
  	err = m.getAuthorizationCollection().Find(bson.M{"username": username, "grantedto": organization}).One(&authorization)
  	if err == mgo.ErrNotFound {
  		err = nil
  	} else if err != nil {
  		authorization = nil
  	}
  	return
  }
docs: //GetAuthorization returns the authorization for a specific organization, nil if no such authorization exists