.add("anEnum", anEnum)
          .toString();
    }
  }

  /** Validates that the Comparator equivalent we document is correct. */
  @J2ktIncompatible // TODO b/315311435 - J2kt cannot emulate Comparator<C>.<U>thenComparing()
  public void testComparatorEquivalent() {
    Comparator<Foo> comparatorUsingComparisonChain =
        (a, b) ->
            ComparisonChain.start()