List<WeightedGroupItem> InitSupplements()
{
var result = new List<WeightedGroupItem> ();
var index = 0;
result.Add (WeightedGroupItem.ForIndex (index++, Type, Group));
if (!string.IsNullOrEmpty (supplements)) {
var elems = supplements.Split (',');
elems.Select (s => s.Trim ()).ForEach (grp =>
result.Add (WeightedGroupItem.ForIndex (index++, Type, grp)));
}
return result;
}