ReferencePriceDto example

        return new self(
            $product->getPurchaseUnit(),
            $product->getReferenceUnit(),
            $product->getUnitId()
        );
    }

    public static function createFromCheapestPrice(CheapestPrice $price): ReferencePriceDto
    {
        return new ReferencePriceDto($price->getPurchase(), $price->getReference(), $price->getUnitId());
    }

    public function getPurchase(): ?float
    {
        return $this->purchase;
    }

    public function setPurchase(?float $purchase): void
    {
        $this->purchase = $purchase;
    }