title: How to stub view model in ui5?
body: <p>I'm new to qunit + sinon.js, I want to write a unit test for function <code>onMultiSelectPress</code>, so I need to mock:</p>
  
  <p><code>this.myController._oList</code></p>
  
  <p><code>this.myController.getResourceBundle()</code></p>
  
  <p><code>this.myController.getModel("masterView")</code></p>
  
  <p>Right? </p>
  
  <p>I'm stuck at get a stub for <code>getModel("masterView")</code>, any suggestion? </p>
  
  <pre><code>onInit : function () {
      var oList = this.byId("list"),
          oViewModel = this._createViewModel();   
      this._oList = oList;
      this.setModel(oViewModel, "masterView");    
  },
  
  _createViewModel : function() {
      return new JSONModel({
          isFilterBarVisible: false,
          filterBarLabel: "",
          delay: 0,
          title: this.getResourceBundle().getText("masterTitleCount", [0]),
          noDataText: this.getResourceBundle().getText("masterListNoDataText"),
          sortBy: "Name",
          groupBy: "None",
          listMode: "SingleSelectMaster",
          showDeleteButton: false
      });
  },
  
  getModel : function (sName) {
      return this.getView().getModel(sName);
  },
  
  onMultiSelectPress : function () {
      var oMasterViewModel = this.getModel("masterView");
  
      switch(this._oList.getMode()) {
          case "MultiSelect":
              oMasterViewModel.setProperty("/listMode", "SingleSelectMaster");
              oMasterViewModel.setProperty("/showDeleteButton", false);
              break;
          case "SingleSelectMaster":
              oMasterViewModel.setProperty("/listMode", "MultiSelect");
              oMasterViewModel.setProperty("/showDeleteButton", true);
              break;
      }
  },
  </code></pre>