title: Why can't I define properties or functions on prototype via Object.defineProperties()?
body: <p>I want to set multiple properties on the prototype of my object at once, since Object.defineProperties() takes an object(and prototype is an object) and descriptors, and my object obj has already a prototype as it comes with every object,i am trying to modify the prototype of my object as follows</p>
  
  <pre><code>var obj = document.createElement(tn);
  
  obj.prototype = Object.defineProperties(obj.prototype,{
      getName:{
          value:function(){
              alert("I have the tag"+this.tagName);
          },
          configurable:true
          }
      });
  </code></pre>
  
  <p>but I am getting an error:</p>
  
  <pre><code>Object.defineProperties called on non-object
  </code></pre>
  
  <p>why?</p>