code: @SuppressWarnings("unchecked")
      public static <Item extends IItem> Item getHolderAdapterItem(@Nullable RecyclerView.ViewHolder holder) {
          if (holder != null) {
              Object tag = holder.itemView.getTag(com.mikepenz.fastadapter.R.id.fastadapter_item_adapter);
              if (tag instanceof FastAdapter) {
                  FastAdapter fastAdapter = ((FastAdapter) tag);
                  int pos = fastAdapter.getHolderAdapterPosition(holder);
                  if (pos != RecyclerView.NO_POSITION) {
                      return (Item) fastAdapter.getItem(pos);
                  }
              }
          }
          return null;
      }
docs: convenient helper method to get the Item from a holder
  
  @param holder the ViewHolder for which we want to retrieve the item
  @return the Item found for this ViewHolder