public function execute($command = '', $cwd = null, array $env = null)
    {
        $fd = proc_open(
            $command,
            $this->descriptors,
            $pipes,
            $cwd,
            $env
        );

        // Close the proc's stdin right away
        fclose($pipes[0]);

        // Read stdout
        $output = $this->parseOutput(stream_get_contents($pipes[1]));
        fclose($pipes[1]);

        $returnCode = (int) trim(proc_close($fd));

        return new CliCommandResponse([
            'output'      => $output,
            'return_code' => $returnCode,
        ]);
    }