public static function findWarning()
 {
     $trackersArray = Database::getTrackersList();
     foreach ($trackersArray as $tracker) {
         $warningsCount = Database::getWarningsCount($tracker);
         if ($warningsCount == 1) {
             $warningsArray = Database::getWarnings($tracker);
             Notification::sendNotification('warning', $warningsArray['time'], $tracker, $warningsArray['reason']);
         }
     }
 }