public RelNode convert(RelNode rel) { final CollectRel collect = (CollectRel) rel; final RelTraitSet traitSet = collect.getTraitSet().replace(EnumerableConvention.INSTANCE); final RelNode input = collect.getChild(); return new EnumerableCollectRel( rel.getCluster(), traitSet, convert(input, input.getTraitSet().replace(EnumerableConvention.INSTANCE)), collect.getFieldName()); } }