Because all the **fields actually change** (the type now includes `None` and they now have a default value of `None`), we need to **re-declare** them.

We don't really need to inherit from `HeroBase` because we are re-declaring all the fields. I'll leave it inheriting just for consistency, but this is not necessary. It's more a matter of personal taste. 🤷

The fields of `HeroUpdate` are:

    if (expected.equals(in)) {
      assertThat(out).isSameInstanceAs(in);
    } else {
      assertThat(out).isEqualTo(expected);
    }
  }

  // Test collapse() a little differently than the rest, as we really want to
  // cover lots of different configurations of input text
  public void testCollapse() {
    // collapsing groups of '-' into '_' or '-'
    doTestCollapse("-", "_");
    doTestCollapse("x-", "x_");

  - [Known Issues](#known-issues)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-16)
    - [Deprecation](#deprecation)
    - [API Change](#api-change-4)
    - [Feature](#feature-8)

   * tests that assert that a certain amount of time has passed, that the method returned `false`,
   * or even that an interrupt occurred (if the spurious wakeup happens before the interrupt).
   *
   * Fundamentally, there's not really anything we can do about that. In the unlikely event that it
   * comes up in practice (maybe through some kind of sanitizer-like testing that intentionally

        return unsafeComparator.isFunctional()
            ? unsafeComparator
            : lexicographicalComparatorJavaImpl();
      } catch (Throwable t) { // ensure we really catch *everything*
        /*
         * Now that UnsafeComparator is implemented to initialize successfully even when we know we
         * can't use it, this `catch` block might now be necessary only:
         *

          }
        },
        directExecutor());
    manager.startAsync();
    afterStarted.countDown();
    // We do not call awaitHealthy because, due to races, that method may throw an exception.  But
    // we really just want to wait for the thread to be in the failure callback so we wait for that
    // explicitly instead.
    failEnter.await();
    assertFalse("State should be updated before calling listeners", manager.isHealthy());

  //    possible to the thing right before the try. You could have
  //    guard.leave(), but that's a little odd as well because the
  //    guard doesn't have anything to do with leaving. You can't
  //    really enforce that the guard you're leaving is the same one
  //    you entered with, and it doesn't actually matter.
  //
  // 2. Since you can enter the monitor without a guard at all, some

    - [Avoiding Collisions in IP allocation to Services](#avoiding-collisions-in-ip-allocation-to-services)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-17)
    - [Deprecation](#deprecation)
    - [API Change](#api-change-4)
    - [Feature](#feature-15)

         * another implementation but also forces AbstractFutureState to be able to do the
         * same—hence the try-catch here.
         *
         * (Really, we're fortunate that breaking AtomicReferenceFieldUpdater doesn't break _even
         * more_ things.)
         */
        helper = new SynchronizedHelper();
      }
    }
    ATOMIC_HELPER = helper;

     *     <li>"snapshot" - query only snapshot repositories to discover versions</li>
     * </ul>
     * Default (when unset) is using request carried nature. Hence, this configuration really makes sense with value
     * {@code "auto"}, while ideally callers needs update and use newly added method on version range request to
     * express preference.
     *
     * @since 4.0.0
     */
    @Config(defaultValue = "release_or_snapshot")