def get_way_points(relation):
    """
    Get way points of OSM relation.

    @param relation: OSM relation as dictionary.
    @return: List of way points (OSM node ids).

    >>> relation_id = 660162
    >>> relation = get_relation_by_id(relation_id)
    >>> way_points = get_way_points(relation)
    """

    return [r['ref'] for r in relation['member'] if r['type'] == 'node']