public async Task <User> AddEvaluator(Guid courseId, string mid) { try { var userDetail = await _userManager.GetUser(mid); if (userDetail != null) { var addEvaluator = await _courseRepository.AddEvaluator(Guid.NewGuid(), userDetail.Id, courseId); if (addEvaluator > 0) { return(userDetail); } } } catch (Exception ex) { } return(null); }