public static String entityUuidOf(String id) {
    if (id.startsWith(ID_PREFIX)) {
      return id.substring(ID_PREFIX.length());
    }
    return id;
  }
@Test
  public void projectUuidOf_fails_with_NPE_if_argument_is_null() {
    assertThatThrownBy(() ->  AuthorizationDoc.entityUuidOf(null))
      .isInstanceOf(NullPointerException.class);
  }