*
   * // is equivalent to
   *
   * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
   *     new ImmutableSetMultimap.Builder<Character, String>()
   *         .put('b', "anana")
   *         .putAll('a', "pple", "sparagus")
   *         .putAll('c', "arrot", "herry")
   *         .build();
   * }</pre>
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */