private int GetValue(BattleInvariant.Type type)
    {
        switch (type)
        {
        default:
            return(0);

        case BattleInvariant.Type.Up:
            return(1);

        case BattleInvariant.Type.Down:
            return(-1);
        }
    }
 public void Add(BattleInvariant.Type type)
 {
     this.threshold += this.GetValue(type);
 }
 public void Remove(BattleInvariant.Type type)
 {
     this.threshold -= this.GetValue(type);
 }