code: public function getItemByPuid($puid)
      {
          foreach ($this->getItems() as $item) {
              if ($item->getPuid() == $puid) {
                  return $item;
              }
          }
  
          throw new CartItemNotFoundException($puid, $this);
      }
docs: @param string $puid
  
  @return CartItem
  
  @throws CartItemNotFoundException