code: public void offsetChildrenVertical(int dy) {
          final int childCount = getChildCount();
          for (int i = 0; i < childCount; i++) {
              getChildAt(i).offsetTopAndBottom(dy);
          }
      }
docs: Offset the bounds of all child views by <code>dy</code> pixels.
  Useful for implementing simple scrolling in {@link com.twotoasters.android.support.v7.widget.RecyclerView.LayoutManager LayoutManagers}.
  
  @param dy Vertical pixel offset to apply to the bounds of all child views