Select a child item by id (str), reference or index.

def move_to(self, id_):
        """Select a child item by id (str), reference or index."""
        if self.items:
            try:
                self.current_item = self.items[id_]
            except (StopIteration, IndexError, NoSuchItem):
                raise NoSuchItem
            for f in self._hooks["select"]:
                f(self, id_)
        return self