@NonNull
    private AlbumEntity buildAlbumInfo(String bucketName, String bucketId) {
        AlbumEntity album = null;
        if (!TextUtils.isEmpty(bucketId)) {
            album = mBucketMap.get(bucketId);
        }
        if (album == null) {
            album = new AlbumEntity();
            if (!TextUtils.isEmpty(bucketId)) {
                album.mBucketId = bucketId;
            } else {
                album.mBucketId = String.valueOf(mUnknownAlbumNumber);
                mUnknownAlbumNumber++;
            }
            if (!TextUtils.isEmpty(bucketName)) {
                album.mBucketName = bucketName;
            } else {
                album.mBucketName = UNKNOWN_ALBUM_NAME;
                mUnknownAlbumNumber++;
            }
            if (album.mImageList.size() > 0) {
                mBucketMap.put(bucketId, album);
            }
        }
        return album;
    }
get the cover and count

@param buckId album id
boxing/src/main/java/com/bilibili/boxing/model/task/impl/AlbumTask.java