public void Buy(IValuablePieceOfPaper paper, double quantity)
{
paper.Quantity -= quantity;
if (Money >= quantity * paper.Price)
{
Money = Math.Round(Money - quantity * paper.Price, 2);
InvestedMoney += quantity * paper.Price;
if (!ownings.Contains(Find(paper.Name, ownings)))
{
ownings.Add(paper.CreateAPair(quantity)); //incapsulated
}
else
{
var paper0 = Find(paper.Name, ownings);
paper0.Quantity += quantity;
paper0.TotalValue = paper0.Price * paper0.Quantity;
}
}
}
