Ordering<Number> k = objects.compound(objects.compound(numbers));

    // You can also arbitrarily assign a more restricted type - not an intended
    // feature, exactly, but unavoidable (I think) and harmless
    Ordering<Integer> l = objects.compound(numbers);

    // This correctly doesn't work:
    // Ordering<Object> m = numbers.compound(objects);

    Ordering<Number> k = objects.compound(objects.compound(numbers));

    // You can also arbitrarily assign a more restricted type - not an intended
    // feature, exactly, but unavoidable (I think) and harmless
    Ordering<Integer> l = objects.compound(numbers);

    // This correctly doesn't work:
    // Ordering<Object> m = numbers.compound(objects);