### Question:
RecyclerViewScrollHandlingDelegate implements ScrollHandlingDelegate { @Override public void pageScrollDown() { if (recyclerView != null) { final int height = recyclerView.getHeight(); recyclerView.smoothScrollBy(0, height); } } RecyclerViewScrollHandlingDelegate(
      @NonNull RequireScrollMixin requireScrollMixin, @Nullable RecyclerView recyclerView); @Override void startListening(); @Override void pageScrollDown();  }### Answer:
@Test public void testClickScrollButton() { mDelegate.pageScrollDown(); verify(mRecyclerView).smoothScrollBy(anyInt(), eq(50)); }