set properties on a store from returned data

store.js

dojo.require('dojo.data.ItemFileReadStore');

// get items from the returned data...is there a better way?
dojo.declare( 'MyDataStore', dojo.data.ItemFileWriteStore, {
  _getItemsFromLoadedData: function(dataObject) {
     this.totalCount = dataObject.totalCount;
     this.inherited(arguemnts);
  }
});
var data = { identifier: "id",
         label: "name",
         totalCount: 42,
         items: [ { id: 1, name: "Foobar" } ] };
var store = new MyDataStore( { data: data });

store.fetch( { onComplete: function(data) { console.log('o hai') }});

console.log( store.totalCount );