public MementoV2 Deposit(int amount)
{
_balance += amount;
var m = new MementoV2(_balance);
_changes.Add(m);
_current++;
return(m);
}
public void Restore(MementoV2 m)
{
if (m == null)
{
return;
}
_balance = m.Balance;
_changes.Add(m);
_current = _changes.Count - 1;
}