task = async (entry) => {
    const src = await entry.getFile();

    const t0 = Date.now();
    return exifTool.read(src)
      .then(tags => storage.writeFile(entry, exifSuffix, tags))
      .then(() => {
        log.debug(t0, `Extracted exif data from ${entry}`);
      })
      .catch(err => {
        log.error(err, `Could not write exif data for ${entry}: ${err}`)
      })
  }
@param {import('@home-gallery/types').TExtractorEntry} entry
@param {callback} cb