code: void pushRecycledView(@NonNull ViewHolder viewHolder) {
          Deque<ViewHolder> deque = mViewHolders.get(viewHolder.getItemType());
          if (deque == null) {
              deque = new ArrayDeque<>();
              mViewHolders.put(viewHolder.getItemType(), deque);
          }
          deque.push(viewHolder);
      }
docs: Add a view to the Recycler. This view may be reused in the function
  {@link #popRecycledViewHolder(int)}
  
  @param viewHolder A viewHolder to add to the Recycler. It can no longer be used.