src/FACTFinder/Adapter/ProductCampaign.php
public function setProductNumbers($productNumbers)
    {
        $parameters = $this->request->getParameters();
        $parameters['productNumber'] = $productNumbers;
        $this->upToDate = false;
    }
public function setProductNumbers($productNumbers)
    {
        $parameters = $this->request->getParameters();
        $parameters['productNumber'] = $productNumbers;
        $this->upToDate = false;
    }
Set one or multiple product numbers to get campaigns for, overwriting any
numbers previously set. Note that multiple numbers will only be considered for
shopping cart campaigns. For product detail campaigns only the first number
will be used.

@param string|string[] $productNumbers One or more product numbers.