static int getDictionaryId(byte[] dictionary) {
    if (!isDictionary(dictionary)) {
      throw new IllegalArgumentException("Not a ZStandard dictionary");
    }
    return ByteBuffer.wrap(dictionary, 4, 4).order(ByteOrder.LITTLE_ENDIAN).getInt();
  }
Returns dictionary and its ID number, useful for comparing to other dictionaries for equality
hbase-compression/hbase-compression-zstd/src/main/java/org/apache/hadoop/hbase/io/compress/zstd/ZstdCodec.java