public void CantEditNotExistingContractor()
        {
            using (EF_ZMT_DbContext.EF_ZMT_DbContext context = new EF_ZMT_DbContext.EF_ZMT_DbContext())
            {
                FixedAssetService transaction = new FixedAssetService();
                context.Context.ExecuteStoreCommand("DELETE FROM Contractor");
                int count = context.Context.Contractors.Count();
                Assert.AreEqual(count, 0);

                Contractor contractor = new Contractor()
                {
                    name = "ABC",
                    city = "Kraków",
                    nip = 555123213,
                    postal_code = "31-987",
                    street = "Królewska",
                    country = "Polska"
                };
                transaction.AddContractor(contractor);

                Contractor contractor2 = new Contractor()
                {
                    name = "XXX",
                    city = "Warszawa",
                    nip = 6666666,
                    postal_code = "22-987",
                    street = "Wrocławska",
                    country = "Polska"
                };
                transaction.EditContractor(contractor2);
                count = context.Context.Contractors.Count();
                Assert.AreEqual(count, 1);
            }
        }
        public void CanEditContractor()
        {
            using (EF_ZMT_DbContext.EF_ZMT_DbContext context = new EF_ZMT_DbContext.EF_ZMT_DbContext())
            {
                FixedAssetService transaction = new FixedAssetService();
                context.Context.ExecuteStoreCommand("DELETE FROM Contractor");
                int count = context.Context.Contractors.Count();
                Assert.AreEqual(count, 0);

                Contractor contractor = new Contractor()
                {
                    name = "ABC",
                    city = "Kraków",
                    nip = 555123213,
                    postal_code = "31-987",
                    street = "Królewska",
                    country = "Polska"
                };
                transaction.AddContractor(contractor);
                count = context.Context.Contractors.Count();
                Assert.AreEqual(count, 1);


                Contractor temp = context.Context.Contractors.FirstOrDefault(x => x.name == "ABC");
                temp.city = "Warszawa";
                temp.street = "Radomska 8";

                transaction.EditContractor(temp);
                count = context.Context.Contractors.Count();
                Assert.AreEqual(count, 1);

                Assert.IsNotNull(temp);
                Assert.AreEqual(temp.nip, 555123213);
                Assert.AreEqual(temp.city, "Warszawa");
                Assert.AreEqual(temp.street, "Radomska 8");
            }
        }