'Wrapper around the field widget\'s `id_for_label` method.
Useful, for example, for focusing on this field regardless of whether
it has a single widget or a MutiWidget.'

def _id_for_label(self):

    widget = self.field.widget
    id_ = (widget.attrs.get(u'id') or self.auto_id)
    return widget.id_for_label(id_)
