presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/MergeFilters.java/MergeFilters/apply
class MergeFilters:    @Override
    public Result apply(FilterNode parent, Captures captures, Context context)
    {
        FilterNode child = captures.get(CHILD);

        return Result.ofPlanNode(
                new FilterNode(
                        parent.getId(),
                        child.getSource(),
                        combineConjuncts(metadata, child.getPredicate(), parent.getPredicate())));
    }