@classmethod
def delete_conntrack_helper(cls, cth, client=None):
    """Delete conntrack helper

        :param client: Client to be used
        If client is not given it will use the client used to create the
        conntrack helper, or cls.client if unknown.
        """
    client = client or cth.get('client') or cls.client
    client.delete_conntrack_helper(cth['router_id'], cth['id'])
