public static String entityUuidOf(String id) {
    if (id.startsWith(ID_PREFIX)) {
      return id.substring(ID_PREFIX.length());
    }
    return id;
  }
@Test
  public void projectUuidOf_returns_argument_if_does_not_starts_with_id_prefix() {
    String id = randomAlphabetic(1 + new Random().nextInt(10));
    assertThat(AuthorizationDoc.entityUuidOf(id)).isEqualTo(id);
    assertThat(AuthorizationDoc.entityUuidOf("")).isEmpty();
  }