ScrollerHelper { public int getCurrX() { return mScroller.getCurrX(); } ScrollerHelper(OverScroller overScroller); boolean startScroll(int start, int end); boolean startScroll(int start, int end, int duration); void finish(); boolean isFinished(); boolean computeScrollOffset(); int getCurrX();  }
@Test public void WhenCurrX_forwardToOverScroll() { scrollerHelper.getCurrX(); verify(overScroller).getCurrX(); }