bool FilterInvasion(InvasionViewModel invasionVM) => invasionItemKeys.Contains(invasionVM.DefenderReward.Item?.Id) || invasionItemKeys.Contains(invasionVM.AttackerReward.Item?.Id);
UserNotification CreateNotification(InvasionViewModel i) => new InvasionUserNotification(i);
public InvasionUserNotification(InvasionViewModel invasion) => Invasion = invasion;