public void TestEditInvoiceDetails()
        {
            InvoiceDetailsController idc = new InvoiceDetailsController();
            System.Web.Mvc.ViewResult result = idc.Index();

            InvoiceDetails id = ((List<InvoiceDetails>)result.ViewData.Model).First();
            System.Web.Mvc.ActionResult invoiceDetailsEdition = idc.Edit(id.InvoiceDetailsID);

            //post edited
            id.Price= 9999;

            System.Web.Mvc.ActionResult resultEdition = idc.Edit(id);
            Assert.IsInstanceOf(typeof(System.Web.Mvc.PartialViewResult), resultEdition);
        }