Drop existing entries from the cache.

        Args:
            hard (bool): If True, all current entries are flushed from the
                server(s), which affects all users. If False, only the local
                process is affected.

def flush(self, hard=False):
        """Drop existing entries from the cache.

        Args:
            hard (bool): If True, all current entries are flushed from the
                server(s), which affects all users. If False, only the local
                process is affected.
        """
        if not self.servers:
            return
        if hard:
            self.client.flush_all()
            self.reset_stats()
        else:
            from uuid import uuid4
            tag = uuid4().hex
            if self.debug:
                tag = "flushed" + tag
            self.current = tag