class OfflineLicenseHelper {

  public synchronized byte[] downloadLicense(DrmInitData drmInitData) throws DrmSessionException {
    Assertions.checkArgument(drmInitData != null);
    return blockingKeyRequest(DefaultDrmSessionManager.MODE_DOWNLOAD, null, drmInitData);
  }

  public  OfflineLicenseHelper(
      UUID uuid,
      ExoMediaDrm<T> mediaDrm,
      MediaDrmCallback callback,
      @Nullable HashMap<String, String> optionalKeyRequestParameters);

}