code: function (helperContainer) {
        if (helperContainer) {
          this.helperContainer = helperContainer;
        } else {
          this.helperContainer = window;
        }
  
        this.reopen({
          willDestroy: function () {
            this._super.apply(this, arguments);
            this.removeTestHelpers();
          }
        });
  
        this.testHelpers = {};
        for (var name in helpers) {
          this.originalMethods[name] = this.helperContainer[name];
          this.testHelpers[name] = this.helperContainer[name] = helper(this, name);
          protoWrap(Test.Promise.prototype, name, helper(this, name), helpers[name].meta.wait);
        }
  
        for (var i = 0, l = injectHelpersCallbacks.length; i < l; i++) {
          injectHelpersCallbacks[i](this);
        }
      }
docs: This injects the test helpers into the `helperContainer` object. If an object is provided
  it will be used as the helperContainer. If `helperContainer` is not set it will default
  to `window`. If a function of the same name has already been defined it will be cached
  (so that it can be reset if the helper is removed with `unregisterHelper` or
  `removeTestHelpers`).
  Any callbacks registered with `onInjectHelpers` will be called once the
  helpers have been injected.
  Example:
  ```
  App.injectTestHelpers();
  ```
  @method injectTestHelpers
  @public