code: public static Integer parseItemLayoutId(Class<? extends ItemViewHolder> itemViewHolderClass) {
          Integer itemLayoutId = ClassAnnotationParser.getLayoutId(itemViewHolderClass);
          if (itemLayoutId == null) {
              throw new LayoutIdMissingException();
          }
          return itemLayoutId;
      }
docs: Parses the layout ID annotation form the itemViewHolderClass