public async Task <IReadOnlyList <ProductType> > GetProductTypesAsync()
 {
     return((await _productTypeStorage.ListAllAsync())
            .Select(t => t.ToCoreEntity())
            .ToList());
 }
 public async Task <IReadOnlyList <ProductBrand> > GetProductBrandsAsync()
 {
     return((await _productBrandStorage.ListAllAsync())
            .Select(b => b.ToCoreEntity())
            .ToList());
 }