private static RelTraitSet getTraitSet(
      RelOptCluster cluster, RelCollation collation, RelDistribution distribution) {
    return TraitsUtil.getDefaultTraitSet(cluster).replace(collation).replace(distribution);
  }
Creates a HiveSortExchange.

@param input     Input relational expression
@param distribution Distribution specification
@param collation Collation specification
@param keys Keys specification
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/reloperators/HiveSortExchange.java