@Test
public void testStdCandidates() {

    Stream<String> candidates = Stream.of("1", "3", "5");
    
    List<Tuple2od<String>> result = recommender.getRecommendation("0", candidates).getItems();
    List<Tuple2od<String>> expected = Arrays.asList(
            tuple("1", 5.0),
            tuple("3", 3.0),
            tuple("5", 1.0)
    );
    
    assertEquals(expected, result);
}