public MajorViewModel(IViewContainer container, string sessionId)
        {
            Container = container;
            SessionId = sessionId;

            Provider = new MajorProvider();
            Provider.MajorEvent = MajorLoadedEvent;
        }
        public MajorComposeViewModel(IViewContainer container, ViewModelRelationship parent,
            string sessionId)
        {
            Parent = parent;
            Container = container;
            SessionId = sessionId;

            majorProvider = new MajorProvider();
            majorProvider.MajorEvent = MajorLoadedEvent;
            majorProvider.MajorEvent += (parent.ViewModel as MajorViewModel).MajorLoadedEvent;
        }