* expression {@code o -> Optional.toJavaUtil(o)} instead.
   *
   * @since NEXT (but since 21.0 in the JRE flavor)
   */
  @SuppressWarnings({
    "AmbiguousMethodReference", // We chose the name despite knowing this risk.
    "Java7ApiChecker",
  })
  // If users use this when they shouldn't, we hope that NewApi will catch subsequent Optional calls
  @IgnoreJRERequirement