input.put("foo", 1);
    ImmutableListMultimap<String, Integer> multimap = ImmutableListMultimap.copyOf(input);
    new EqualsTester().addEqualityGroup(input, multimap).testEquals();
  }

  public void testCopyOfEmpty() {
    ArrayListMultimap<String, Integer> input = ArrayListMultimap.create();
    ImmutableListMultimap<String, Integer> multimap = ImmutableListMultimap.copyOf(input);