public async Task IdOfNonexistentSupplier_GetSupplierProduct_ReturnNotFound()
{
const int supplierId = -1;
const int productId = 10;
var exception = await Assert.ThrowsAsync <ProblemDetailsException>(() =>
_suppliersController.GetSupplierProduct(supplierId, productId));
Assert.Equal(StatusCodes.Status404NotFound, exception.Details.Status);
Assert.Contains("supplier", exception.Details.Title, StringComparison.OrdinalIgnoreCase);
}