new ImmutableListMultimap.Builder<Integer, String>()
            .put(4, "Inky")
            .put(6, "Blinky")
            .put(5, "Pinky")
            .put(5, "Pinky")
            .put(5, "Clyde")
            .build();

    List<String> badGuys = Arrays.asList("Inky", "Blinky", "Pinky", "Pinky", "Clyde");
    Function<String, Integer> stringLengthFunction =

   *
   * {@snippet :
   * List<String> badGuys = Arrays.asList("Inky", "Blinky", "Pinky", "Pinky", "Clyde");
   * Function<String, Integer> stringLengthFunction = ...;
   * Multimap<Integer, String> index = Multimaps.index(badGuys, stringLengthFunction);
   * System.out.println(index);
   * }
   *
   * <p>prints
   *
   * {@snippet :
   * {4=[Inky], 6=[Blinky], 5=[Pinky, Pinky, Clyde]}
   * }
   *

   *
   * {@snippet :
   * List<String> badGuys = Arrays.asList("Inky", "Blinky", "Pinky", "Pinky", "Clyde");
   * Function<String, Integer> stringLengthFunction = ...;
   * Multimap<Integer, String> index = Multimaps.index(badGuys, stringLengthFunction);
   * System.out.println(index);
   * }
   *
   * <p>prints
   *
   * {@snippet :
   * {4=[Inky], 6=[Blinky], 5=[Pinky, Pinky, Clyde]}
   * }
   *