public void AddApplication(Application app)
 {
     foreach (Application a in applications)
     {
         if (a.Id == app.Id)
         {
             return;
         }
     }
     applications.Add(app);
 }
 public void RemoveApplication(Application app)
 {
     if (applications.Contains(app))
     {
         applications.Remove(app);
     }
 }