/// <summary>
/// 必要艦種（艦種と必要数を指定）
/// </summary>
public static Cond RequiredShip(int n, ShipTypeID type) =>
new Cond($"{Constants.GetShipTypeNameShort((int)type)}が{n}隻必要",
f => f.MembersInstance.Count(s => s?.MasterShip?.ShipType == (int)type) >= n);
/// <summary>
/// 旗艦の艦種
/// </summary>
public static Cond FlagShipType(ShipTypeID type) =>
new Cond($"旗艦指定：{Constants.GetShipTypeNameShort((int)type)}",
f => f.MembersInstance?[0]?.MasterShip?.ShipType == (int)type);