/**
  * This is the constructor of the Product Price object.
  *
  * @author David Pauli <*****@*****.**>
  * @param String $productID The product ID to which this price belongs.
  * @param ProductPriceType $type The type of the product price.
  * @param mixed[] $priceParameter The price parameter.
  * @param mixed[] $quantityParameter The quantity parameter.
  * @since 0.1.2
  * @since 0.2.0 Merge with ProductPriceWithQuantity.
  */
 public function __construct($productID, $type, $priceParameter, $quantityParameter)
 {
     // if the first parameter is no product ID
     if (!InputValidator::isProductID($productID)) {
         Logger::warning("ep6\\ProductPrice\nNew product price has no product ID (" . $type . "," . $priceParameter . ").");
         $this->errorSet("PP-1");
         return;
     }
     $this->productID = $productID;
     $this->type = $type;
     parent::__construct($priceParameter, $quantityParameter);
 }