/**
  * @return Users
  */
 public function getAssistants()
 {
     global $db;
     $time = time();
     $users = array();
     $query = "SELECT b.*, a.*\n                    FROM `permissions` AS a\n                    LEFT JOIN `" . AUTH_DATABASE . "`.`user_data` AS b\n                    ON b.`id` = a.`assigned_to`\n                    WHERE a.`assigned_by`=?\n                    AND (a.`valid_from` = '0' OR a.`valid_from` <= ?) AND (a.`valid_until` = '0' OR a.`valid_until` > ?)\n                    ORDER BY `valid_until` ASC";
     $results = $db->GetAll($query, array($this->getID(), $time, $time));
     if ($results) {
         foreach ($results as $result) {
             $user = Assistant::fromArray($result);
             $users[] = $user;
         }
     }
     return new Users($users);
 }