private void OnUserAddedToDataStore(object sender, UserChangedEventArgs args)
{
_stream.PauseStream();
if (args.NewUser != null)
{
_stream.AddFollow(args.NewUser.Id);
}
if (args.OldUser != null)
{
_stream.RemoveFollow(args.OldUser.Id);
}
_stream.ResumeStream();
}