class MediaBrowser2 extends MediaController2 {

    public void getChildren(@NonNull String parentId, int page, int pageSize,
            @Nullable Bundle extras) {
        if (parentId == null) {
            throw new IllegalArgumentException("parentId shouldn't be null");
        }
        if (page < 1 || pageSize < 1) {
            throw new IllegalArgumentException("Neither page nor pageSize should be less than 1");
        }
        MediaBrowserCompat browser = getBrowserCompat();
        if (browser == null) {
            return;
        }

        Bundle options = MediaUtils2.createBundle(extras);
        options.putInt(MediaBrowserCompat.EXTRA_PAGE, page);
        options.putInt(MediaBrowserCompat.EXTRA_PAGE_SIZE, pageSize);
        browser.subscribe(parentId, options, new GetChildrenCallback(parentId, page, pageSize));
    }

    public  MediaBrowser2(@NonNull Context context, @NonNull SessionToken2 token,
            @NonNull /*@CallbackExecutor*/ Executor executor, @NonNull BrowserCallback callback);

}