### Question:
ThumbnailAdapter extends RecyclerView.Adapter<ThumbnailViewHolder> { @Override public int getItemCount() { if (cursor == null) { return 0; } else { return cursor.getCount(); } } ThumbnailAdapter(EventBus eventBus); void setCursor(Cursor cursor); @Override ThumbnailViewHolder onCreateViewHolder(ViewGroup parent, int viewType); @Override void onBindViewHolder(ThumbnailViewHolder holder, int position); @Override int getItemCount();  }### Answer:
@Test public void testNullCursor() { assertEquals(0, adapter.getItemCount()); }