code: public final CartLn findCartItemById(final Cart pShoppingCart,
      final Long pCartItemItsId) throws Exception {
      CartLn cartLn = null;
      for (CartLn ci : pShoppingCart.getItems()) {
        if (ci.getItsId().equals(pCartItemItsId)) {
          if (ci.getDisab()) {
            throw new ExceptionWithCode(ExceptionWithCode.SOMETHING_WRONG,
              "requested_item_disabled");
          }
          cartLn = ci;
          break;
        }
      }
      if (cartLn == null) {
        throw new ExceptionWithCode(ExceptionWithCode.SOMETHING_WRONG,
          "requested_item_not_found");
      }
      return cartLn;
    }
docs: <p>Find cart item by ID.</p>
  @param pShoppingCart cart
  @param pCartItemItsId cart item ID
  @return cart item
  @throws Exception - an exception