private void OnTestExpandRow (object sender, Gtk.TestExpandRowArgs args)
{
bool filled = (bool) store.GetValue (args.Iter, FilledCol);
Repository parent = (Repository) store.GetValue (args.Iter, RepositoryCol);
if (!filled) {
store.SetValue (args.Iter, FilledCol, true);
FullRepoNode (parent, args.Iter);
} else
args.RetVal = false;
}