ScrollViewScrollHandlingDelegate implements ScrollHandlingDelegate, BottomScrollListener { @Override public void pageScrollDown() { if (mScrollView != null) { mScrollView.pageScroll(ScrollView.FOCUS_DOWN); } } ScrollViewScrollHandlingDelegate(
            @NonNull RequireScrollMixin requireScrollMixin,
            @Nullable ScrollView scrollView); @Override void onScrolledToBottom(); @Override void onRequiresScroll(); @Override void startListening(); @Override void pageScrollDown();  }
@Test public void testPageScrollDown() throws Throwable { mDelegate.pageScrollDown(); verify(mScrollView).smoothScrollBy(anyInt(), eq(50)); }