backbone.js change url parameter of a Model and fetch does not update data fetched
===

I have the following Model:

    window.MyModel = Backbone.Model.extend({
         initialize: function(props){
              this.url = props.url;
         } 

         parse: function(){

              // @override- parsing data fetched from URL
         }


    });

     // instantiate
      var mod = new MyModel({url: 'some/url/here'});


I use this global variable 'mod' to fetch some data into this model from backend. 


     // fetch

     mod.fetch({
           success: function(){ ...},
           error: ...

     });

All above works well....
My Issue: I want to reuse this model by changing resetting the url and call fetch but it does not update the url somehow. I have tried the following:

      mod.fetch({ 
           data: {url:'/some/other/url'},
           postData: true,
           success: function(){ //process data},
           error: ...
      });


     mod.set({url: '/some/other/url'});
     // called fetch() without data: and postData: attributes as mentioned in previous

How do I set the url for my model so that I could call fetch() and it fetches data from updated url? Am I missing something. Thanks for any pointers..
 

