/**
  * singleton
  *
  * @return Timetracker_Controller
  */
 public static function getInstance()
 {
     if (self::$_instance === NULL) {
         self::$_instance = new Timetracker_Controller();
     }
     return self::$_instance;
 }
 /**
  * singleton
  *
  * @return Timetracker_Controller
  */
 public static function getInstance()
 {
     if (self::$_instance === NULL) {
         self::$_instance = new self();
     }
     return self::$_instance;
 }