@Test
public void multipliesWeights() {

    Overlap instance = someOverlap();
    Overlaps overlaps = new Overlaps();
    Model model = () -> asSet(instance.getPattern());
    ProductWeightFunction weightFunction = new ProductWeightFunction(w((o, os, m) -> 0.5), w((o, os, m) -> 0.5));
    assertThat(weightFunction.getWeight(instance, overlaps, model), is(0.25));
}