public IHttpActionResult GetAuthentication(User user, string apiKey)
        {
            if (!ModelState.IsValid)
            {
                return(Content(HttpStatusCode.BadRequest, "BadRequest"));
            }

            var userDb = UsersLogic.GetAuthentication(user, apiKey);

            if (userDb == null)
            {
                return(Content(HttpStatusCode.NotFound, "NotFound2"));
            }

            return(Content(HttpStatusCode.OK, userDb));
        }