/** {@inheritDoc} */
  @Override
  protected Map<SignatureType, SignatureFileInfo> doInBackground()
      throws SignatureManagerException {
    Map<SignatureType, SignatureFileInfo> downloaded =
        new HashMap<SignatureType, SignatureFileInfo>();

    for (SignatureFileInfo update : updates) {
      if (!update.hasError()) {
        downloaded.put(update.getType(), signatureManager.downloadLatest(update.getType()));
      }
    }

    return downloaded;
  }