def delete(self, msg, claim_id=None):
        """
        Deletes the specified message from its queue. If the message has been
        claimed, the ID of that claim must be passed as the 'claim_id'
        parameter.
        """
        msg_id = utils.get_id(msg)
        if claim_id:
            uri = "/%s/%s?claim_id=%s" % (self.uri_base, msg_id, claim_id)
        else:
            uri = "/%s/%s" % (self.uri_base, msg_id)
        return self._delete(uri)