@Test
public void testMostSimilarToMultipleExcludeIfNotSimilarToAll() throws Exception {

  ItemBasedRecommender recommender = buildRecommender2();
  List<RecommendedItem> similar = recommender.mostSimilarItems(new long[] {3, 4}, 2);
  assertNotNull(similar);
  assertEquals(1, similar.size());
  RecommendedItem first = similar.get(0);
  assertEquals(0, first.getItemID());
  assertEquals(0.2f, first.getValue(), EPSILON);
}