/**
  * Get an instance of this class.
  *
  * @return GFPayPalPaymentsPro
  */
 public static function get_instance()
 {
     if (self::$_instance == null) {
         self::$_instance = new GFPayPalPaymentsPro();
     }
     return self::$_instance;
 }
function gf_paypalpaymentspro()
{
    return GFPayPalPaymentsPro::get_instance();
}