public string AssignedProducts(Guid?brandId)
{
if (!brandId.HasValue)
{
return(null);
}
var brand = _brandQueries.GetBrandOrNull(brandId.Value);
var assignedProductsIds = brand.Products.Select(x => x.ProductId).ToList();
return(SerializeJson(_gameQueries.GetAssignedProductsData(assignedProductsIds)));
}