public sealed class CMatch : Contract<CMatch> {
        [Output] public CMap Map { get; private set; }

        [Input] public readonly ReactiveCommand            Start = new ReactiveCommand();
        [Input] public readonly ReactiveCommand            Leave = new ReactiveCommand();
        [Input] public readonly ReactiveProperty<TimeSpan> Timer = new ReactiveProperty<TimeSpan>();

        [Output] public readonly ReactiveProperty<int>        PlayerId  = new ReactiveProperty<int>();
        [Output] public readonly ReactiveProperty<MatchState> State     = new ReactiveProperty<MatchState>();
        [Output] public readonly ReactiveProperty<MatchMode>  MatchMode = new ReactiveProperty<MatchMode>();
        [Output] public readonly ReactiveProperty<GameMode>   GameMode  = new ReactiveProperty<GameMode>();

        protected override void Initialize() {
            this.Map = this.GetSub<CMap>();
        }
    }