// @target: esnext
// @useDefineForClassFields: true
class Animal {
    _sound = 'rustling noise in the bushes'

    get sound() { return this._sound }
    set sound(val) {
      this._sound = val;
      /* some important code here, perhaps tracking known sounds, etc */
    }

    makeSound() {
        console.log(this._sound)
    }
}

const a = new Animal
a.makeSound() // 'rustling noise in the bushes'

class Lion extends Animal {
    sound = 'RAWR!' // error here
}

const lion = new Lion
lion.makeSound() // with [[Define]]: Expected "RAWR!" but got "rustling noise in the bushes"