code: public final void notifyContentItemInserted(int position) {
          int newHeaderItemCount = getHeaderItemCount();
          int newContentItemCount = getContentItemCount();
          if (position < 0 || position >= newContentItemCount) {
              throw new IndexOutOfBoundsException("The given position " + position + " is not within the position bounds for content items [0 - " + (newContentItemCount - 1) + "].");
          }
          notifyItemInserted(position + newHeaderItemCount);
      }
docs: Notifies that a content item is inserted.
  
  @param position the position of the content item.