public function execute($command, callable $next)
    {
        $filename = $command->getFile()->path();
        $this->apiDocBuilder->debug('Starting to parse file: ' . $filename);
        try {
            return $next($command);
        } catch (\Exception $e) {
            $this->apiDocBuilder->log('Unable to parse file "' . $filename . '", ' . $e->getMessage());
        }
        return null;
    }