presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/RemoveAggregationInSemiJoin.java/RemoveAggregationInSemiJoin/apply
class RemoveAggregationInSemiJoin:    @Override
    public Result apply(SemiJoinNode semiJoinNode, Captures captures, Context context)
    {
        AggregationNode filteringSource = captures.get(CHILD);
        return Result.ofPlanNode(semiJoinNode
                .replaceChildren(ImmutableList.of(semiJoinNode.getSource(), getOnlyElement(filteringSource.getSources()))));
    }