code: public static function getInstance($cfg = array())
      {
          if (!isset(self::$instance)) {
              return false;
          } elseif ($cfg) {
              self::$instance->setCfg($cfg);
          }
          return self::$instance;
      }
docs: Returns the *Singleton* instance of this class (IF INSTANCE EXISTS)
  
  @param array $cfg optional config
  
  @return object|false