public void TestGetAllFollowerId()
{
mockFollowRepository.Setup(x => x.GetAllFollowerId(It.IsAny <string>())).Returns(getAllFollowerId);
var followService = new FollowService(mockFollowRepository.Object);
List <string> getAllFollowerIds = followService.GetAllFollowerId("5d111299f3b75e0001f4ed78");
string followerIdFirstActual = getAllFollowerIds.FirstOrDefault();
Assert.AreEqual(followerIdFirstActual, "5d0a17701a0a4200017de6c7");
}