/**
  * singleton
  *
  * @return Sales_Controller
  */
 public static function getInstance()
 {
     if (self::$_instance === NULL) {
         self::$_instance = new Sales_Controller();
     }
     return self::$_instance;
 }
 /**
  * Get Config for Sales
  * @return array
  */
 public function getConfig()
 {
     return Sales_Controller::getInstance()->getConfig();
 }