code: @Override
      public void onViewDetachedFromWindow(RecyclerView.ViewHolder viewHolder, int position) {
          IItem item = FastAdapter.getHolderAdapterItemTag(viewHolder);
          if (item != null) {
              item.detachFromWindow(viewHolder);
              if (viewHolder instanceof FastAdapter.ViewHolder) {
                  ((FastAdapter.ViewHolder) viewHolder).detachFromWindow(item);
              }
          }
      }
docs: is called in onViewDetachedFromWindow when the view is detached from the window
  
  @param viewHolder the viewHolder for the type at this position
  @param position   the position of this viewHolder