@Test
public void setRoot() {

    activity.setContentView(uut.getView());
    disablePushAnimation(child1, child2, child3);
    assertThat(uut.isEmpty()).isTrue();
    uut.push(child1, new CommandListenerAdapter());
    uut.push(child2, new CommandListenerAdapter());
    assertThat(uut.getTopBar().getTitleBar().getNavigationIcon()).isNotNull();
    uut.setRoot(child3, new CommandListenerAdapter() {
        @Override
        public void onSuccess(String childId) {
            assertContainsOnlyId(child3.getId());
            assertThat(uut.getTopBar().getTitleBar().getNavigationIcon()).isNull();
        }
    });
}