public static function getInstance()
 {
     if (null === self::$instance) {
         self::$instance = new ImplementationLoader();
     }
     return self::$instance;
 }
 public static function getInstance()
 {
     if (null === self::$instance) {
         global $dbConn;
         $fixturePath = realpath(__DIR__ . '/fixtures/doctrine');
         self::$instance = new ImplementationLoader($dbConn, $fixturePath);
     }
     return self::$instance;
 }