presto-main/src/main/java/io/prestosql/sql/planner/plan/JoinNode.java/JoinNode/flipType
class JoinNode:    private static Type flipType(Type type)
    {
        switch (type) {
            case INNER:
                return INNER;
            case FULL:
                return FULL;
            case LEFT:
                return RIGHT;
            case RIGHT:
                return LEFT;
            default:
                throw new IllegalStateException("No inverse defined for join type: " + type);
        }
    }