public Boxing withIntent(Context context, Class<?> cls, ArrayList<? extends BaseMedia> selectedMedias) {
        mIntent.setClass(context, cls);
        if (selectedMedias != null && !selectedMedias.isEmpty()) {
            mIntent.putExtra(EXTRA_SELECTED_MEDIA, selectedMedias);
        }
        return this;
    }
{@link Intent#setClass(Context, Class)} with input medias.
boxing/src/main/java/com/bilibili/boxing/Boxing.java