Returns a child item iterator.
        iterator([flags]) returns an iterator for the tree widget itself
        iterator(item,[flags]) returns an iterator for a tree widget item

def iterator(self, *args):
        """Returns a child item iterator.
        iterator([flags]) returns an iterator for the tree widget itself
        iterator(item,[flags]) returns an iterator for a tree widget item
        """
        if len(args) > 1:
            return ClickableTreeWidget.Iterator(*args)
        else:
            return ClickableTreeWidget.Iterator(self, *args)