docs: public void setProduct(final String product) {
          if (product == null && this.product == null) {
              return;
          } else if (product == null) {
              removeChild(this.product);
              this.product = null;
          } else if (this.product == null) {
              this.product = new KeyValueNode<String>(CommonConstants.CS_PRODUCT_TITLE, product);
              appendChild(this.product, false);
          } else {
              this.product.setValue(product);
          }
      }