def int_to_mode(mode):
    """Returns the string representation in VPP of a given bondethernet mode,
    or "" if 'mode' is not a valid id.

    See src/vnet/bonding/bond.api and schema.yaml for valid pairs."""

    ret = {1: "round-robin", 2: "active-backup", 3: "xor", 4: "broadcast", 5: "lacp"}
    try:
        return ret[mode]
    except KeyError:
        pass
    return ""