inheritance-class-b.js

class B extends A {
  handleClick = () => {
    super.handleClick();

    console.log("B.handleClick");
  }

  handleLongClick() {
    super.handleLongClick();

    console.log("B.handleLongClick");
  }
}

console.log(B.prototype);
// A {constructor: ƒ, handleLongClick: ƒ}

console.log(B.prototype.__proto__);
// {constructor: ƒ, handleLongClick: ƒ}

new B().handleClick();
// Uncaught TypeError: (intermediate value).handleClick is not a function

new B().handleLongClick();
// A.handleLongClick
// B.handleLongClick