@Test
public void testHashCode() {

  Set<QualifiedRecommendation> hashSet = new HashSet<>();
  hashSet.add(DEFAULT_QUALIFIED_RECOMMENDATION);
  hashSet.add(CLONED_DEFAULT_QUALIFIED_RECOMMENDATION);
  Assert.assertEquals(1, hashSet.size());
  hashSet.addAll(ALL_MUTATIONS);
  Assert.assertEquals(1 + ALL_MUTATIONS.size(), hashSet.size());
}