public async void TestReturnContractors()
        {
            var options = new DbContextOptionsBuilder <Databasecontext
                                                       >().UseInMemoryDatabase(databaseName: "Test")
                          .Options;

            using (var context = new Databasecontext(options))
            {
                var contractor = new Contractor("test1", "test2", "test3", "test4", "test5");
                context.Add(contractor);
                context.SaveChanges();
                ContractorsController ContractorPositions = new ContractorsController(context);

                var contractors = await ContractorPositions.GetContractors();

                IEnumerable <Contractor> result = contractors.Value;
                Assert.Single(result);
                Assert.Equal("test1", result.Last().Username);
            }
        }