public static function getAgencies()
 {
     $dbObj = DBPool::getInstance();
     $agencies = $dbObj->get_results("SELECT * FROM agency");
     if ($dbObj->num_rows > 0) {
         $agencyArray = array();
         foreach ($agencies as $a) {
             $agencyObj = new Agency();
             $agencyObj->setId($a->id);
             $agencyObj->setTitle($a->title);
             $agencyObj->setShortTitle($a->short_title);
             $agencyObj->setDefaultVehicleType($a->default_vehicle);
             $agencyArray[$a->short_title] = $agencyObj;
         }
         return $agencyArray;
     } else {
         throw new Exception("There are no agencies in the database");
     }
 }