/**
  * Main PayPal Instance, ensures only one instance is/can be loaded
  *
  * @see wc_paypal_express()
  * @return WC_PayPal_Express
  * @since 2.0
  */
 public static function instance()
 {
     if (is_null(self::$instance)) {
         self::$instance = new self();
     }
     return self::$instance;
 }
 /**
  * Supposed to return the main gatewya plugin class, but we don't have one of those
  *
  * @see \WCS_SV_API_Base::get_plugin()
  * @return object
  * @since 2.0
  */
 protected function get_plugin()
 {
     return WCS_PayPal::instance();
 }