public function getNetworks()
 {
     if ($this->networks == null) {
         $this->networks = NetworkUtil::getNetworksByAid($this->id);
     }
     return $this->networks;
 }
 public static function getReportsByAid($aid, $startDate, $endDate, $numCat = 4)
 {
     return ReportUtil::getReportsByIdAndGroup('aid', $aid, 'type', $startDate, $endDate, NetworkUtil::getNetworksByAid($aid), $numCat);
 }