public override void Add(BaseElement element)
{
Pair pairNew = element as Pair;
// check existsing item and remove it
foreach (Pair item in Items)
{
if (item.Key == pairNew.Key)
{
Items.Remove(item);
break;
}
}
// add
Items.Add(pairNew);
}
// Methods public abstract void Add(BaseElement element);