public IHttpActionResult Put(int?id, [FromBody] AnswerVM answerVM)
 {
     if (id == null || answerVM == null || !answerVM.isWalid())
     {
         return(BadRequest());
     }
     try
     {
         _answerService.Change(id.GetValueOrDefault(), (Mapper.Map <AnswerDTO>(answerVM)));
     }
     catch (BILException myExc)
     {
         return(InternalServerError(myExc));
     }
     return(Ok());
 }