assertNull(map.get(null));
  }

  public void testAsMultimap() {
    ImmutableMap<String, Integer> map =
        ImmutableMap.of("one", 1, "won", 1, "two", 2, "too", 2, "three", 3);
    ImmutableSetMultimap<String, Integer> expected =
        ImmutableSetMultimap.of("one", 1, "won", 1, "two", 2, "too", 2, "three", 3);
    assertEquals(expected, map.asMultimap());
  }

  public void testAsMultimapWhenEmpty() {