private void turn(char turnDirection) {

        if (turnDirection == 'L') {
            setFacing(getFacing() - 1);
        }
        else if (turnDirection == 'R') {
            setFacing(getFacing() + 1);
        }

        //keeps the directional constants within the bounds
        if (getFacing() < NORTH) {
            setFacing(WEST);
        }
        else if (getFacing() > WEST) {
            setFacing(NORTH);
        }
    }