/**
  * 
  * @return \GF\Config
  */
 public static function getInstance()
 {
     if (self::$_instance == NULL) {
         self::$_instance = new \GF\Config();
     }
     return self::$_instance;
 }
 /**
  * @return Config|null
  */
 public static function getInstance()
 {
     if (self::$_instance == null) {
         self::$_instance = new Config();
     }
     return self::$_instance;
 }