获取工具栏'；Android'；用户界面集成测试框架

我有一个片段，它将用户当前正在编辑的实体的标题设置为：

        Activity activity = this.getActivity();
        CollapsingToolbarLayout appBarLayout = (CollapsingToolbarLayout) activity.findViewById(R.id.toolbar_layout);
        if (appBarLayout != null) {
            appBarLayout.setTitle(mItem.name);
        }

class DetailWrapper {

    protected UiObject2 find( BySelector selector ){
        device.wait(Until.findObject(selector), 2 * 1000);
        return device.findObject(selector);
    }

    public ItemView hasName(String itemName) throws Exception {
        UiObject2 title = find(By.text(itemName));
        assertEquals(title.getText(), itemName);
        return this;
    }
}

在测试代码中，我成功地导航到片段，但是我无法通过以下文本定位元素：

        Activity activity = this.getActivity();
        CollapsingToolbarLayout appBarLayout = (CollapsingToolbarLayout) activity.findViewById(R.id.toolbar_layout);
        if (appBarLayout != null) {
            appBarLayout.setTitle(mItem.name);
        }

class DetailWrapper {

    protected UiObject2 find( BySelector selector ){
        device.wait(Until.findObject(selector), 2 * 1000);
        return device.findObject(selector);
    }

    public ItemView hasName(String itemName) throws Exception {
        UiObject2 title = find(By.text(itemName));
        assertEquals(title.getText(), itemName);
        return this;
    }
}

hasName（String）中的title在assert中始终为null，尽管它位于具有正确标题的正确活动中。断言AppBar标题的最佳方法是什么