### Question:
IdGenerator { public static final String shortUuid() { ShortUuid.Builder builder = new ShortUuid.Builder(); ShortUuid shortUuid = builder.build(UUID.randomUUID()); return shortUuid.toString(); }  static final String shortUuid(); static String uuid();  }### Answer:
@Test public void short_uuid_22_characters() { String uuid = IdGenerator.shortUuid(); assertThat(uuid.length()).isLessThanOrEqualTo(22); }