public void Update_Administrator()
        {
            PersonalDataDB pddb  = PddbTestingInstance.GetPddbInstanceForTesting();
            IAdministrator admin = pddb.ListAdministrators().Single();

            pddb.UpdateAdministrator(admin.ID, new AdministratorUpdateModel(admin.ID, "999", "*****@*****.**", "666", "satan", "super"));

            var administrators = pddb.ListAdministrators();

            Assert.Single(administrators);

            admin = pddb.ListAdministrators().Single();

            Assert.Equal("Karel Admin", admin.FullName);
            Assert.Equal("999", admin.Phone);
            Assert.Equal("*****@*****.**", admin.Email);
            Assert.Equal("666", admin.OfficeNumber);
            Assert.Equal("satan", admin.InternalPhoneNumber);
            Assert.Equal("super", admin.Supervisor);
        }