@Override
    public int decodeWriterId(int bucketProperty) {
      return bucketProperty;
    }
This is the "legacy" version.  The whole {@code bucket} value just has the bucket ID in it.
The numeric code for this version is 0. (Assumes bucket ID takes less than 29 bits... which
implies top 3 bits are 000 so data written before Hive 3.0 is readable with this scheme).
ql/src/java/org/apache/hadoop/hive/ql/io/BucketCodec.java