protected static $openAPITypes = [
        'available_quantity' => 'int',
        'category_id' => 'string',
        'charity' => '\TNT\Ebay\Sell\Inventory\V1\Model\Charity',
        'extended_producer_responsibility' => '\TNT\Ebay\Sell\Inventory\V1\Model\ExtendedProducerResponsibility',