public Boxing withIntent(Context context, Class<?> cls, ArrayList<? extends BaseMedia> medias, int pos, String albumId) {
        mIntent.setClass(context, cls);
        if (medias != null && !medias.isEmpty()) {
            mIntent.putExtra(EXTRA_SELECTED_MEDIA, medias);
        }
        if (pos >= 0) {
            mIntent.putExtra(EXTRA_START_POS, pos);
        }
        if (albumId != null) {
            mIntent.putExtra(EXTRA_ALBUM_ID, albumId);
        }
        return this;
    }
use to start image viewer.

@param medias  selected medias.
@param pos     the start position.
@param albumId the specify album id.
boxing/src/main/java/com/bilibili/boxing/Boxing.java