Comparator of strings that sorts them in any arbitrary order, giving precedence to prescribed stings

ArbitraryStringComparator.java

public class ArbitraryStringComparator implements Comparator<String> {
    private final ImmutableList<String> stringsInOrder;

    private ArbitraryStringComparator(String... stringsInOrder) {
        this.stringsInOrder = ImmutableList.copyOf(stringsInOrder);
    }

    @Override
    public int compare(String o1, String o2) {
        if (stringsInOrder.contains(o1) && stringsInOrder.contains(o2)) {
            return stringsInOrder.indexOf(o1) - stringsInOrder.indexOf(o2);
        }
        if (stringsInOrder.contains(o1)) {  // && !stringsInOrder.contains(o2)
            return -1;
        }
        if (stringsInOrder.contains(o2)) {  // && !stringsInOrder.contains(o1)
            return 1;
        }
        return o1.compareTo(o2);            // !stringsInOrder.contains(o1) && !stringsInOrder.contains(o2)
    }
}

private static Comparator<String> getArbitraryStringComparator(String... stringsInOrder) {
    // The list and the comparator are both reversed to get the argument strings first, and then the other elements
    Comparator<String> arbitraryComparator = 
            comparing(s -> ImmutableList.copyOf(stringsInOrder).reverse().indexOf(s));
    return arbitraryComparator.reversed().thenComparing(naturalOrder());
}