code: public function indexAction()
      {
          /* @var $request \Zend\Http\Request */
          $request = $this->getRequest();
          $this->httpClient->setMethod(Request::METHOD_POST);
          $this->httpClient->setParameterPost(['dsl_text' => $request->getPost('dsl_text')]);
          $response = $this->httpClient->send();
  
          if (! $response->isSuccess()) {
              throw new \UnexpectedValueException('HTTP Request failed');
          }
  
          /* @var $redirect \Zend\Mvc\Controller\Plugin\Redirect */
          $redirect = $this->plugin('redirect');
  
          return $redirect->toUrl('https://yuml.me/' . $response->getBody());
      }
docs: Redirects the user to a YUML graph drawn with the provided `dsl_text`
  
  @return \Zend\Http\Response
  
  @throws \UnexpectedValueException if the YUML service answered incorrectly