public HttpResponseMessage Post(RelationRepresentation representation)
 {
     try
     {
         var relation = Mapper.Map <IRelation>(representation);
         RelationService.Save(relation);
         return(Request.CreateResponse(HttpStatusCode.OK, CreateRepresentation(relation)));
     }
     catch (ModelValidationException exception)
     {
         return(Request.CreateResponse(HttpStatusCode.BadRequest, exception.Errors));
     }
 }
        public HttpResponseMessage Put(int id, RelationRepresentation rel)
        {
            try
            {
                var found = RelationService.GetById(id);
                if (found == null)
                {
                    return(Request.CreateResponse(HttpStatusCode.NotFound));
                }

                Mapper.Map(rel, found);
                RelationService.Save(found);

                return(Request.CreateResponse(HttpStatusCode.OK, CreateRepresentation(found)));
            }
            catch (ModelValidationException exception)
            {
                return(Request.CreateResponse(HttpStatusCode.BadRequest, exception.Errors));
            }
        }