CollectionView extends FrameLayout { @SuppressWarnings("unchecked") void setItems(List<?> items) { if (adapter != null) { adapter.onBindItems(items); } } CollectionView(
      @NonNull Context context,
      @Nullable AttributeSet attrs); @SuppressWarnings("unchecked") @Override void onAttachedToWindow(); @Override void onDetachedFromWindow(); void setAdapter(@NonNull Adapter adapter);  }
@Test public void testSetItems() throws Exception { final List<Integer> items = Arrays.asList(1, 2, 3); tested.setItems(items); Mockito.verify(mockedAdapter).onBindItems(eq(items)); }