Examine the code below and identify the compilation error:

Examine the code below and identify the compilation error:

abstract class Appliance {
    abstract void operate();
}
class Washer extends Appliance {
    void operate() {
        System.out.println("Washing clothes");
    }
}
class Dryer extends Appliance {
}
public class Test {
    public static void main(String[] args) {
        Appliance d = new Dryer();
        d.operate();
    }
}