public IHttpActionResult Post(Guid companyId, AnnouncementInputModel model)
        {
            Severity severity = (Severity)Enum.Parse(typeof(Severity), model.Severity, true);
            var announcement = new Announcement(companyId, model.Message, model.Name, severity, model.StartDate, model.EndDate);

            if (model.IsActive.HasValue && model.IsActive.Value)
            {
                announcement.Activate();
            }
            else if (model.IsActive.HasValue && !model.IsActive.Value)
            {
                announcement.Deactivate();
            }

            AnnouncementRepository.Add(announcement);

            return Created(new Uri(Url.Link("GetAnnouncement", new { companyId = announcement.CompanyId, announcementId = announcement.Id })), AnnouncementModel.From(announcement));
        }