code: def __unbind_call(self, still_valid):
          
          with self._lock:
              if self.__timer is not None:
                  # Timeout expired, we're not valid anymore
                  self.__timer = None
                  self.__still_valid = still_valid
                  self._ipopo_instance.unbind(
                      self, self.__timer_args[0], self.__timer_args[1]
                  )
docs: Calls the iPOPO unbind method