private ArtifactStatus(String key, int rank) {
        this.rank = rank;
        this.key = key;

        if (map == null) {
            map = new HashMap<>();
        }
        map.put(key, this);
    }

    public static ArtifactStatus valueOf(String status) {
        ArtifactStatus retVal = null;

        if (status != null) {
            retVal = map.get(status);
        }