def delete_permissions(self, grp_name, resource, url_prefix, auth, session, send_opts):
        """
        Args:
            grp_name (string): Name of group.
            resource (intern.resource.boss.BossResource): Identifies which data model object to operate on.
            url_prefix (string): Protocol + host such as https://api.theboss.io
            auth (string): Token to send in the request header.
            session (requests.Session): HTTP session to use for request.
            send_opts (dictionary): Additional arguments to pass to session.send().

        Raises:
            requests.HTTPError on failure.
        """
        filter_params = {"group": grp_name}
        filter_params.update(resource.get_dict_route())

        req = self.get_permission_request('DELETE', 'application/json',
                                          url_prefix, auth, query_params=filter_params)
        prep = session.prepare_request(req)
        resp = session.send(prep, **send_opts)
        if resp.status_code == 204:
            return

        msg = ('Failed deleting permissions to group {}, got HTTP response: ({}) - {}'.format(
            grp_name, resp.status_code, resp.text))
        raise HTTPError(msg, request=req, response=resp)