code: func (d *GoogleGCSDownloader) ListFilesInBuild(job string, buildNumber int, prefix string) ([]string, error) {
  	return d.GoogleGCSBucketUtils.ListFilesInBuild(job, buildNumber, prefix)
  }
docs: // ListFilesInBuild returns the contents of the files with the specified prefix
  // for the test job at the given buildNumber.