class DownloadOkHttp3Connection implements DownloadConnection, DownloadConnection.Connected {

    @Override public Connected execute() throws IOException {
        request = requestBuilder.build();
        response = client.newCall(request).execute();
        return this;
    }

      DownloadOkHttp3Connection(@NonNull OkHttpClient client,
                              @NonNull Request.Builder requestBuilder);
      DownloadOkHttp3Connection(@NonNull OkHttpClient client, @NonNull String url);

}