code: public LdapUser updateLdapUser(final LdapUser transientUser) {
          final LdapUser user = getObjectById(LdapUser.class, transientUser.getId());
          pm.currentTransaction().begin();
          user.setDN(transientUser.getDN());
          pm.currentTransaction().commit();
          return pm.getObjectById(LdapUser.class, user.getId());
      }
docs: Updates the specified LdapUser.
  @param transientUser the optionally detached LdapUser object to update.
  @return an LdapUser
  @since 1.0.0