*
 * <p>An instance may be called concurrently by multiple threads to process different entries.
 * Implementations of this interface should avoid performing blocking calls or synchronizing on
 * shared resources.
 *
 * @param <K> the most general type of keys this listener can listen for; for example {@code Object}
 *     if any key is acceptable

@SuppressWarnings("serial") // uses writeReplace(), not default serialization
@ElementTypesAreNonnullByDefault
final class SingletonImmutableSet<E> extends ImmutableSet<E> {
  // We deliberately avoid caching the asList and hashCode here, to ensure that with
  // compressed oops, a SingletonImmutableSet packs all the way down to the optimal 16 bytes.

  final transient E element;

  SingletonImmutableSet(E element) {

* Keep commits discrete. Avoid including multiple unrelated changes in a single commit.
* Keep commits self-contained. Avoid spreading a single change across multiple commits. A single commit should make sense in isolation.

### Testing changes

After making changes, you can test your code in 2 ways:

//
// DeviceThread itself is thread-safe, in that StartExecute will block if there
// is a pending execution. Since StartExecute is equivalent to grabbing a lock,
// multiple DeviceThreads should always be accessed in the same order to avoid
// deadlocks.
class DeviceThread {
 public:
  // Starts a background thread waiting for `StartExecute`.
  explicit DeviceThread(const std::string& device, const bool is_async,

   *     the {@link ExecutionException} thrown by {@code input.get()} or, if {@code get()} throws a
   *     different kind of exception, that exception itself. To avoid hiding bugs and other
   *     unrecoverable errors, callers should prefer more specific types, avoiding {@code
   *     Throwable.class} in particular.

`/<user-running-minio>/.minio/certs`.

*Tip*: In a standard Kubernetes configuration, this will be `/root/.minio/certs`. Kubernetes will mount the secrets volume read-only,

      Class<X> exceptionType, ClosingFunction<? super X, ? extends V> fallback, Executor executor) {
    return catchingMoreGeneric(exceptionType, fallback, executor);
  }

  // Avoids generic type capture inconsistency problems where |? extends V| is incompatible with V.
  private <X extends Throwable, W extends V> ClosingFuture<V> catchingMoreGeneric(

    }
    if (right == null) {
      return LEFT_IS_GREATER;
    }
    return ordering.compare(left, right);
  }

  @Override
  @SuppressWarnings("nullness") // should be safe, but not sure if we can avoid the warning
  public <S extends @Nullable T> Ordering<S> reverse() {
    // ordering.reverse() might be optimized, so let it do its thing
    return ordering.<T>reverse().<@NonNull S>nullsLast();
  }

		return nil, nil, errInvalidArgument
	}

	// prepare getElapsedTime() to calculate elapsed time since we started trying formatting disks.
	// All times are rounded to avoid showing milli, micro and nano seconds
	formatStartTime := time.Now().Round(time.Second)
	getElapsedTime := func() string {
		return time.Now().Round(time.Second).Sub(formatStartTime).String()
	}

	var (

	_, err := objAPI.DeleteObject(ctx, minioMetaBucket, configFile, ObjectOptions{
		DeletePrefix:       true,
		DeletePrefixObject: true, // use prefix delete on exact object (this is an optimization to avoid fan-out calls)
	})
	if err != nil && isErrObjectNotFound(err) {
		return errConfigNotFound
	}
	return err
}