public void AddDistrict_Success_Test()
{
// Arrange
DistrictDTO dto = SampleDistrictDTO(1);
// create mock for repository
var mock = new Mock <IDistrictRepository>();
mock.Setup(s => s.AddDistrict(Moq.It.IsAny <R_District>())).Returns(1);
// service
DistrictService districtService = new DistrictService();
DistrictService.Repository = mock.Object;
// Act
int id = districtService.AddDistrict(dto);
// Assert
Assert.AreEqual(1, id);
Assert.AreEqual(1, dto.DistrictId);
}