/**
  * @param EcommercePaymentRequest $paymentRequest
  * @return string url
  */
 public function render(EcommercePaymentRequest $paymentRequest)
 {
     $parameters = $paymentRequest->toArray();
     $parameters[PaymentRequest::SHASIGN_FIELD] = $paymentRequest->getShaSign();
     return $paymentRequest->getPostFinanceUri() . '?' . http_build_query($parameters);
 }