public SessionByIdModelProvider(Session s)
 {
     this.s = s;
     this.Sessions = new ObservableCollection<Session>();
 }
 public SessionByIdModelProvider SessionByIdModelProvider(Session s)
 {
     SessionByIdModelProvider provider = null;
     if (!_sessionByIdModelProvider.ContainsKey(s))
     {
         provider = new SessionByIdModelProvider(s);
         provider.LoadData();
         _sessionByIdModelProvider.Add(s, provider);
     }
     else
     {
         provider = _sessionByIdModelProvider[s];
     }
     return provider;
 }