private SliderAdapter getRealAdapter() {
   PagerAdapter adapter = mViewPager.getAdapter();
   if (adapter != null) {
     return ((InfinitePagerAdapter) adapter).getRealAdapter();
   }
   return null;
 }
 private InfinitePagerAdapter getWrapperAdapter() {
   PagerAdapter adapter = mViewPager.getAdapter();
   if (adapter != null) {
     return (InfinitePagerAdapter) adapter;
   } else {
     return null;
   }
 }