@RequiresSession
  public PrincipalTypeEntity findById(Integer id) {
    return entityManagerProvider.get().find(PrincipalTypeEntity.class, id);
  }
Find a principal type with the given id.

@param id  type id

@return  a matching principal type  or null
ambari-server/src/main/java/org/apache/ambari/server/orm/dao/PrincipalTypeDAO.java