code: def off(self, events, callback):
          
          if isinstance(events, (str, unicode)):
              events = [events]
          for event in events:
              for callback_obj in self._on_off_events[event]:
                  if callback_obj['callback'] == callback:
                      try:
                          del self._on_off_events[event]
                      except KeyError:
                          pass
docs: Removes the given *callback* from the given *events* (string or list of
          strings).