@Transactional
  public void create(Set<UserEntity> users) {
    for (UserEntity user : users) {
      entityManagerProvider.get().persist(user);
    }
  }
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