text: ﻿function extend(Child, Parent) {
      Child.prototype = Object.create(Parent.prototype);
      Child.prototype.constructor = Child;
  }
  
  function Shape() {}
  Shape.prototype.duplicate = function() {
      console.log('duplicate');
  };
  
  function Circle() {}
  extend(Circle, Shape);
  
  Circle.prototype.duplicate = function() {
      Shape.prototype.duplicate.call(this);
      console.log('duplicate Circle');
  };
  
  const c = new Circle(1, 'red');
  console.log(c);
  