public Comparator<T> getParameterLengthComparator() {
    return parmeterLengthComparator;
  }
@return Returns a {@link Comparator} instance which can be used to determine the longest element in the 
list IN clause parameters. This is required to be able to estimate the final legth of the command.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/txn/jdbc/InClauseBatchCommand.java