@Override
 public List<NetworkVO> listByZoneSecurityGroup(Long zoneId) {
   SearchCriteria<NetworkVO> sc = ZoneSecurityGroupSearch.create();
   if (zoneId != null) {
     sc.setParameters("dataCenterId", zoneId);
   }
   sc.setJoinParameters("services", "service", Service.SecurityGroup.getName());
   return search(sc, null);
 }
 @Override
 public List<NetworkVO> listSecurityGroupEnabledNetworks() {
   SearchCriteria<NetworkVO> sc = SecurityGroupSearch.create();
   sc.setJoinParameters("services", "service", Service.SecurityGroup.getName());
   return listBy(sc);
 }