docs: public Result processPayment(Payment payment) throws PaytrailException {
  		try {
  			String data = marshaller.objectToString(payment);
  			String url = serviceUrl + "/api-payment/create";
  			
  			IOHandlerResult requestResult = postJsonRequest(url, data);
  			
  			if (requestResult.getCode() != 201) {
  				JsonError jsonError = marshaller.stringToObject(JsonError.class, requestResult.getResponse());
  				throw new PaytrailException(jsonError.getErrorMessage());
  	  	}
  			
  			return marshaller.stringToObject(Result.class, requestResult.getResponse());
  		} catch (IOException e) {
  			throw new PaytrailException(e);
  		}
  	}