Getting Toolbar's title with Android's UI integration test framework

I have an fragment which set's the title to the entity the user is currently editing as follows:

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

In the testing code I successfully navigate to the fragment, however I'm unable to locate the element by the text as follows:

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;
    }
}

title in hasName(String) is always null in the assert despite being on the correct activity with the correct title. What is the best method to assert the AppBar's title?