src/Entities/Products/Product.php
public function getExtraSetByID($extraSetID)
    {
        foreach ($this->getExtraSets() as $extraSet) {
            if ($extraSet->getId() == $extraSetID) {
                return $extraSet;
            }
        }

        foreach ($this->getUnlockableExtraSets() as $extraSet) {
            if ($extraSet->getId() == $extraSetID) {
                return $extraSet;
            }
        }

        return null;
    }
public function getExtraSetByID($extraSetID)
    {
        foreach ($this->getExtraSets() as $extraSet) {
            if ($extraSet->getId() == $extraSetID) {
                return $extraSet;
            }
        }

        foreach ($this->getUnlockableExtraSets() as $extraSet) {
            if ($extraSet->getId() == $extraSetID) {
                return $extraSet;
            }
        }

        return null;
    }
@param $extraSetID

@return ProductExtraSet|null