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