@Override
  public RelBuilder filter(Iterable<? extends RexNode> predicates) {
    final RexNode x = RexUtil.composeConjunction(
        cluster.getRexBuilder(), predicates, false);
    if (!x.isAlwaysTrue()) {
      final RelNode input = build();
      final RelNode filter = HiveRelFactories.HIVE_FILTER_FACTORY.createFilter(input, x);
      return this.push(filter);
    }
    return this;
  }
Creates a {@link RelBuilderFactory} that uses a given set of factories.
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/HiveRelBuilder.java