def install_ssl_certs(instances):
    certs = []
    if CONF.object_store_access.public_identity_ca_file:
        certs.append(CONF.object_store_access.public_identity_ca_file)
    if CONF.object_store_access.public_object_store_ca_file:
        certs.append(CONF.object_store_access.public_object_store_ca_file)
    if not certs:
        return
    with context.ThreadGroup() as tg:
        for inst in instances:
            tg.spawn(inst.instance_id % "configure-ssl-cert-%s",
                     _install_ssl_certs, inst, certs)
dataset/ETHPy150Open openstack/sahara/sahara/swift/swift_helper.py/install_ssl_certs/swapped operands of `%`