/**
  * @param DI $di
  */
 public function __construct(DI $di = null)
 {
     if (!class_exists('\\Whoops\\Run')) {
         return;
     }
     if (!$di) {
         $di = DI::getDefault();
     }
     // There's only ever going to be one error page...right?
     $di->setShared('whoops.pretty_page_handler', function () use($di) {
         return (new DebugbarHandler())->setDi($di);
     });
     // There's only ever going to be one error page...right?
     $di->setShared('whoops.json_response_handler', function () {
         $jsonHandler = new JsonResponseHandler();
         $jsonHandler->onlyForAjaxRequests(true);
         return $jsonHandler;
     });
     $di->setShared('whoops', function () use($di) {
         $run = new Run();
         $run->silenceErrorsInPaths(array('/phalcon-debugbar/'), E_ALL);
         $run->pushHandler($di['whoops.pretty_page_handler']);
         $run->pushHandler($di['whoops.json_response_handler']);
         return $run;
     });
     $di['whoops']->register();
 }