}

  /**
   * Returns a stream consisting of the results of applying the given function to the elements of
   * {@code stream} and their indices in the stream. For example,
   *
   * {@snippet :
   * mapWithIndex(
   *     Stream.of("a", "b", "c"),
   *     (e, index) -> index + ":" + e)
   * }
   *
   * <p>would return {@code Stream.of("0:a", "1:b", "2:c")}.
   *
   * <p>The resulting stream is <a