ScrollerHelper { public boolean startScroll(int start, int end) { if (start == end) { return false; } int delta = end - start; mScroller.startScroll(start, 0, delta, 0); return true; } 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 WhenSrtAndEndAreDifferent_startScrollOnOverScroll() { scrollerHelper.startScroll(0, 100); verify(overScroller).startScroll(0, 0, 100, 0); }
@Test public void WhenSrtAndEndAreTheSame_noStartScrollOnOverScroll() { scrollerHelper.startScroll(0, 0); verify(overScroller, never()).startScroll(anyInt(), anyInt(), anyInt(), anyInt()); }