def clear(self):
        """
        Cleans up the manager. The manager can't be used after this method has
        been called
        """
        # Cancel timer
        self.__cancel_timer()
        self.__timer = None
        self.__timer_args = None

        self.__still_valid = False
        self._value = None
        super(TemporalDependency, self).clear()
Cleans up the manager. The manager can't be used after this method has
        been called