presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/EliminateCrossJoins.java/EliminateCrossJoins/isOriginalOrder
class EliminateCrossJoins:    public static boolean isOriginalOrder(List<Integer> joinOrder)
    {
        for (int i = 0; i < joinOrder.size(); i++) {
            if (joinOrder.get(i) != i) {
                return false;
            }
        }
        return true;
    }