使用Android Espresso测试时如何单击操作栏上的项目？

Espresso具有

openActionBarOverflowOrOptionsMenu(Contextcontext)

import static android.support.test.espresso.Espresso.openActionBarOverflowOrOptionsMenu;@Testpublic void testClickInsertItem() {    openActionBarOverflowOrOptionsMenu(InstrumentationRegistry.getInstrumentation().getTargetContext());    onView(withId(R.id.action_insert)).perform(click());}