function render(ServerRequestInterface $request, ResponseInterface $response, $error = null)
 {
     if ($error) {
         // On debug mode, a debugging error popup is displayed for Exceptions/Errors.
         if ($this->devEnv && Http::clientAccepts($request, 'text/html')) {
             return ErrorConsole::display($error, $this->responseFactory->makeHtmlResponse());
         }
         $status = $error instanceof HttpException ? $error->getCode() : 500;
         // Errors may contain an additional `getTitle()` method.
         if (method_exists($error, 'getTitle')) {
             // The title is assumed to be a plain, one-line string (no formatting). If not, make it so.
             $title = $error->getTitle();
             $message = $error->getMessage();
         } else {
             list($title, $message) = array_pad(explode(PHP_EOL, $error->getMessage(), 2), 2, '');
         }
         $response = $response->withStatus($status);
     } else {
         $status = $response->getStatusCode();
         $title = $response->getReasonPhrase();
         $message = strval($response->getBody());
     }
     /** @var ResponseInterface $response */
     $response = $response->withBody($body = $this->responseFactory->makeBody());
     // Otherwise, errors are rendered into a format accepted by the HTML client.
     if (Http::clientAccepts($request, 'text/html')) {
         $response = $response->withHeader('Content-Type', 'text/html');
         $customRenderer = $this->settings->getCustomRenderer($status);
         if ($customRenderer) {
             if ($customRenderer instanceof RenderableInterface) {
                 $class = $customRenderer->getContextClass();
                 $customRenderer->setContext($this->injector->make($class));
             }
             $response = $customRenderer($request, $response, nop());
         } else {
             ob_start();
             $this->htmlTemplate($status, $title, $message);
             $body->write(ob_get_clean());
         }
     } else {
         $title = strip_tags($title);
         $message = strip_tags($message);
         if (Http::clientAccepts($request, 'text/plain') || Http::clientAccepts($request, '*/*')) {
             $response = $response->withHeader('Content-Type', 'text/plain');
             $body->write("{$title}\n{$message}");
         } elseif (Http::clientAccepts($request, 'application/json')) {
             $response = $response->withHeader('Content-Type', 'application/json');
             $body->write(json_encode(['error' => ['code' => $status, 'message' => $title, 'info' => $message]], JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
         } elseif (Http::clientAccepts($request, 'application/xml')) {
             $response = $response->withHeader('Content-Type', 'application/xml');
             $body->write("<?xml version=\"1.0\"?><error><code>{$status}</code><message>{$title}</message><info>{$message}</info></error>");
         }
     }
     // else render nothing
     return $response;
 }
function &gen(&$var)
{
    (yield nop($var));
}