title: how to show message from function decorator?
body: <p>I want to display a message with the size of coffee when I call the method to.String</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>function Coffe(name) {
      this.name = name;
      this.cost = function () {
          return 5;
      };
      this.toString = function () {
          return this.name + this.cost() + ' USD '+ this.size;
      }
  }
  var small = function (size) {
      this.size = size;
      size = "small";
      var cost = coffe.cost();
      coffe.cost = function () {
          return cost - 1;
      }
  };
  var coffe = new Coffe('Latte ');
  small(coffe);
  console.log(String(coffe));</code></pre>
  </div>
  </div>
  </p>