new Function<String, Integer>() {
        @Override
        public Integer apply(String input) {
          return input.length();
        }
      };

  public void testAsMap() {
    Set<String> strings = ImmutableSet.of("one", "two", "three");
    Map<String, Integer> map = Maps.asMap(strings, LENGTH_FUNCTION);
    assertEquals(ImmutableMap.of("one", 3, "two", 3, "three", 5), map);