presto-main/src/main/java/io/prestosql/cost/JoinStatsRule.java/JoinStatsRule/flippedCriteria
class JoinStatsRule:    private List<JoinNode.EquiJoinClause> flippedCriteria(JoinNode node)
    {
        return node.getCriteria().stream()
                .map(EquiJoinClause::flip)
                .collect(toImmutableList());
    }