class enemy {
    constructor() {
        foostate = new stateFoo(this);
        barstate = new stateBar(this);
        // more states.


        // assign a default state:
        currentstate = foostate;
    }

    // called each frame.
    update() {
        currentstate->run();
    }

    setState(newstate) {
        currentstate = newstate;
    }


};