async def clear(self, namespace=None, _conn=None):
        """
        Clears the cache in the cache namespace. If an alternative namespace is given, it will
        clear those ones instead.

        :param namespace: str alternative namespace to use
        :param timeout: int or float in seconds specifying maximum timeout
            for the operations to last
        :returns: True
        :raises: :class:`asyncio.TimeoutError` if it lasts more than self.timeout
        """
        start = time.monotonic()
        ret = await self._clear(namespace, _conn=_conn)
        logger.debug("CLEAR %s %d (%.4f)s", namespace, ret, time.monotonic() - start)
        return ret