public Map<String, String> getParts() {
    return Collections.emptyMap();
  }
Return the different parts of the key. By default, this returns an empty map. Consumers can
choose to override this to provide their own names and types of parts of the key.

@return map of parts name to their type
hbase-handler/src/java/org/apache/hadoop/hive/hbase/HBaseCompositeKey.java