code: def rebind(self, tks):
          
          self._tks = tks
          for tk in self._tks:
              tk.unbind_all(self._tk_event)
              func_id = tk.bind(self._tk_event, self._event_callback)
              self._func_ids.append(func_id)
docs: Rebinds the tk event, only used if a widget has been destroyed
          and recreated.