public function write(Crontab $crontab)
{
$tmpFile = tempnam(sys_get_temp_dir(), 'cron');
$this->writeToFile($crontab, $tmpFile);
$process = new Process($this->crontabCommand($crontab) . ' ' . $tmpFile);
$process->run();
$this->error = $process->getErrorOutput();
$this->output = $process->getOutput();
return $this;
}