code: function(url, callback) {
        
        // TODO: if url is not in the same domain, we should use jsonp !
        util.Connect.asyncRequest('GET', url, { 
           success: function(o) {
              try {
                 this._smd = lang.JSON.parse(o.responseText);
                 this.process(callback);
              }
              catch(ex) {
                 if(lang.isObject(console) && lang.isFunction(console.log))
                    console.log(ex);
                 if( lang.isFunction(callback.failure) ) {
                    callback.failure.call(callback.scope || this, {error: ex});
                 }
              }
           }, 
           failure: function(o) {
              if( lang.isFunction(callback.failure) ) {
                 callback.failure.call(callback.scope || this, {error: "unable to fetch url "+url});
              }
           },
           scope: this
        });
     }
docs: Download the SMD at the given url
  @method fetch
  @param {String} Absolute or relative url