Car2.kt

public interface Car {

    void accelerate();
}

public interface EngineType {
    void turnOnEngine();
}

/***********************/

public class MotorCar implements Car, EngineType {

    private Engine engine;


    public void turnOnEngine() {
        //turn on the engine!
        engine.on();
    }

    public void accelerate() {
        //move forward!
        engine.powerOn(1000);
    }
}

/***********************/

public class ElectricCar implements Car {

    public void accelerate() {
        //this acceleration is crazy!
    }
}