protected void verify(List<Entry<String, Collection<Integer>>> elements) {
        assertEquals(new HashSet<>(elements), multimap.asMap().entrySet());
      }
    }.test();
  }

  public void testKeysSpliterator() {
    List<Entry<String, Integer>> expectedEntries =
        asList(
            immutableEntry("foo", 2),
            immutableEntry("foo", 3),
            immutableEntry("bar", 4),