public function testModifyRequest()
 {
     $request = new Request();
     $e = new CgiExecuteEvent('event', $request);
     $e->modifyRequest(function (RequestInterface $request) {
         return $request->withHeader('Content-Type', 'text/html')->withMethod('POST');
     });
     $this->assertSame(['Content-Type' => ['text/html']], $e->getRequest()->getHeaders());
     $this->assertSame('POST', $e->getRequest()->getMethod());
     $this->assertNotSame($request, $e->getRequest());
 }