public IActionResult AddCandidate(AddCandidateVM candidate)
 {
     if (candidate == null || !ModelState.IsValid)
     {
         return(BadRequest());
     }
     try
     {
         var result = this._candidateService.Insert(candidate.ToCandidate());
         return(CreatedAtAction(nameof(AddCandidate), result));
     }
     catch (Exception ex)
     {
         return(StatusCode(StatusCodes.Status500InternalServerError, ex.Message));
     }
 }