@Nullable
    private ArrayList<BaseMedia> parseSelectedMedias(Bundle savedInstanceState, Bundle argument) {
        ArrayList<BaseMedia> selectedMedias = null;
        if (savedInstanceState != null) {
            selectedMedias = savedInstanceState.getParcelableArrayList(Boxing.EXTRA_SELECTED_MEDIA);
        } else if (argument != null) {
            selectedMedias = argument.getParcelableArrayList(Boxing.EXTRA_SELECTED_MEDIA);
        }
        return selectedMedias;
    }
to clear all medias the first time(the page number is 0). do some clean work.
boxing/src/main/java/com/bilibili/boxing/AbsBoxingViewFragment.java