public StringArrayWidget()
{
this.Build ();
optionColumn = new TreeViewColumn();
CellRendererText optionRender = new CellRendererText();
optionColumn.PackStart(optionRender, true);
optionColumn.AddAttribute(optionRender, "text", 0);
optionTreeView.AppendColumn(optionColumn);
model = new ListStore(typeof(string));
optionTreeView.Model = model;
optionTreeView.Selection.Mode = SelectionMode.Multiple;
}