public function verify(Input $input)
    {
        $this->eventDispatcher->dispatch(new ExerciseRunnerEvent('cgi.verify.start', $this->exercise, $input));
        $result = new CgiResult(
            array_map(
                function (RequestInterface $request) use ($input) {
                    return $this->checkRequest($request, $input->getArgument('program'));
                },
                $this->exercise->getRequests()
            )
        );
        $this->eventDispatcher->dispatch(new ExerciseRunnerEvent('cgi.verify.finish', $this->exercise, $input));
        return $result;
    }