code: func (d *GoogleGCSDownloader) GetFile(job string, buildNumber int, filePath string) (io.ReadCloser, error) {
  	response, err := d.GoogleGCSBucketUtils.GetFileFromJenkinsGoogleBucket(job, buildNumber, filePath)
  	if err != nil {
  		return nil, err
  	}
  	return response.Body, nil
  }
docs: // GetFile returns readcloser of the desired file.