def close(self, end_time=None):
        """
        Close the trace entity by setting `end_time`
        and flip the in progress flag to False. Also decrement
        parent segment's ref counter by 1.

        :param int end_time: Epoch in seconds. If not specified
            current time will be used.
        """
        super(Subsegment, self).close(end_time)
        self.parent_segment.decrement_ref_counter()
Close the trace entity by setting `end_time`
        and flip the in progress flag to False. Also decrement
        parent segment's ref counter by 1.

        :param int end_time: Epoch in seconds. If not specified
            current time will be used.