public int AddItem(int listID, Item newItem, bool checkID = true)
{
if (ExistingId == null)
{
ElementUtils.GetExsistingIDs(this);
}
var key = GetListKey(listID);
if (checkID)
{
if (ExistingId.Contains(Convert.ToInt32(newItem.GetByKey("ID"))))
{
newItem.SetByKey("ID", GetFreeId());
}
}
// if (print) PrintInfo(newItem);
var it = ElementUtils.AdvancedCopy(GetFirstInList(listID), newItem);
AddItem(key, it);
return(it.GetByKey("ID"));
}