/// <summary>
/// Get a string of the Stock by a type of order
/// </summary>
/// <param name="order">by what comperiosn to sort</param>
/// <returns></returns>
public IEnumerable <Box> GetStock()
{
List <Box> stock = new List <Box>();
_mainTree.TraverseInOrder(x => x.InnerTree.TraverseInOrder(y => stock.Add(new Box {
Id = y.Id, X = x.X, Y = y.Y, Count = y.Count, TimeLastPurchase = y.DateNode.Data.TimeLastPurchase
})));
return(stock);
}