    @Ignore
    @Test
    public void gsVariant() {

        GSLambdaRecommendations recommendations = new GSLambdaRecommendations(makePurchases());
        MutableMap<Integer, MutableList<Integer>> results = recommendations.calculateRecommendations();
             
        Assert.assertEquals(4, results.get(5).get(0).intValue());
        Assert.assertEquals(5, results.get(4).get(0).intValue());
    }