def METHOD_NAME(nics, ethtool_opts):
    net_attrs = {'bonding': 'james',
                 'custom': ethtool_opts,
                 'bootproto': 'dhcp', 'STP': 'no', 'bridged': 'true'}
    for subcommand in _parse_into_subcommands(
            net_attrs['custom']['ethtool_opts'].split(' ')):
        _validate_dev_ownership(nics, 'test_net', subcommand)