public IEnumerable<TitleViewModel> GetEmployeeTitleHistory(int employeeId)
 {
     var request = new GetEmployeeTitleHistoryRequest(employeeId);
         var response = this.employeeService.GetTitleHistory(request);
         if (response != null && response.Exception == null)
         {
             return response.TitleHistory.ToList();
         }
     return null;
 }
        public GetEmployeeTitleHistoryResponse GetTitleHistory(
            GetEmployeeTitleHistoryRequest getEmployeeTitleHistoryRequest)
        {
            var response = new GetEmployeeTitleHistoryResponse();

            var titles = this.titleRepository.GetTitleHistory(getEmployeeTitleHistoryRequest.Id);

            if (titles != null)
            {
                response.TitleHistory = titles.ConvertToViewModels();
            }
            else
            {
                response.Exception = this.GetGenericResourceNotFoundException();
            }
            return response;
        }