public BattleStat(IStatFormula formula, BattleStatType statType, IEnumerable <decimal>?modifiers = null)
 {
     Formula   = formula;
     StatType  = statType;
     Value     = 1;
     Modifiers = modifiers?.ToList() ?? new List <decimal>();
 }
 public IBattleStat Build(BattleStatType type)
 {
     return(new BattleStat(Formula, type, Modifiers));
 }