有什么好方法可以将方法声明为“返回此”？

class C {

    typeof(this) foo() { return this; }

}

class Entity {

    typeof(this) refresh();

    typeof(this) clone();

    typeof(this) detach();

}

class FooEntity extends Entity {

    @Override
    typeof(this) detach() {
        fooLink21.removeRef(this); 
        bar39.detach(); 
        return this; 
    }

    void doSomeInteresting() {}
}

fooEntity.clone().detach().doSomeInteresting();

class Parent<C extends Parent> {

   public C getMe (){
      return this;
   }
}

class Sub extends Parent<Sub> { }

abstract class Entity {
    public static <T extends Entity> T detach(T entity) {
        entity.detach();
        return entity;
    }
    protected abstract void detach();
}

import static Entity.detach;

detach(fooEntity).doSomeInteresting();