code: public function getChangeDate($identifier)
      {
          $this->process->execute('fossil finfo -b -n 1 composer.json', $output, $this->checkoutDir);
          list($ckout, $date, $message) = explode(' ', trim($output), 3);
  
          return new \DateTime($date, new \DateTimeZone('UTC'));
      }
docs: {@inheritdoc}