code: public function getChangeDate($identifier)
      {
          if ($this->gitDriver) {
              return $this->gitDriver->getChangeDate($identifier);
          }
  
          $resource = $this->getApiUrl() . '/repos/'.$this->owner.'/'.$this->repository.'/commits/'.urlencode($identifier);
          $commit = JsonFile::parseJson($this->getContents($resource), $resource);
  
          return new \DateTime($commit['commit']['committer']['date']);
      }
docs: {@inheritdoc}