@Transactional
  public void remove(Set<UserEntity> users) {
    for (UserEntity userEntity : users) {
      entityManagerProvider.get().remove(entityManagerProvider.get().merge(userEntity));
    }
  }
Find the user entity for the given admin principal entity.

@param principal the principal entity
@return the matching user entity
ambari-server/src/main/java/org/apache/ambari/server/orm/dao/UserDAO.java