private CardBox?GetPreviousLevelBox(CardBoxLevel level)
{
var previousLevelBoxIndex = _cardBoxes.FindLastIndex(b => b.Level < level);
return(previousLevelBoxIndex != -1 ? _cardBoxes[previousLevelBoxIndex] : null);
}
private CardBox?GetNextLevelBox(CardBoxLevel level)
{
var nextLevelBoxIndex = _cardBoxes.FindIndex(b => b.Level > level);
return(nextLevelBoxIndex != -1 ? _cardBoxes[nextLevelBoxIndex] : null);
}