// Act & Assert
        // unwrap to interface itself should return same instance
        CredentialsInternal unwrapped = creds.unwrap(CredentialsInternal.class);
        assertNotNull(unwrapped, "unwrap to CredentialsInternal returns instance");
        assertSame(creds, unwrapped, "unwrap returns the same object instance");

        // unwrap to unrelated type should return null (use another Credentials implementation)

  public String toString() {
    return super.toString();
  }

  private static boolean isProxyOfSameInterfaces(Object arg, Class<?> proxyClass) {
    return proxyClass.isInstance(arg)
        // Equal proxy instances should mostly be instance of proxyClass
        // Under some edge cases (such as the proxy of JDK types serialized and then deserialized)
        // the proxy type may not be the same.

    //                                                                           =========
    private static final GroupDbm _instance = new GroupDbm();

    private GroupDbm() {
    }

    public static GroupDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

    //                                                                           =========
    private static final RequestHeaderDbm _instance = new RequestHeaderDbm();

    private RequestHeaderDbm() {
    }

    public static RequestHeaderDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

      }
    } catch (Throwable t) {
      // ensure we really catch *everything*
    }

    return JavaLittleEndianBytes.INSTANCE;
  }

  // Compare AbstractFuture.VarHandleAtomicHelperMaker.
  private enum VarHandleLittleEndianBytesMaker {
    INSTANCE {
      /**
       * Implementation used by non-J2ObjC environments (aside, of course, from those that have

    //                                                                           =========
    private static final CrawlingInfoDbm _instance = new CrawlingInfoDbm();

    private CrawlingInfoDbm() {
    }

    public static CrawlingInfoDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

internal fun <T> readFieldOrNull(
  instance: Any,
  fieldType: Class<T>,
  fieldName: String,
): T? {
  var c: Class<*> = instance.javaClass
  while (c != Any::class.java) {
    try {
      val field = c.getDeclaredField(fieldName)
      field.isAccessible = true
      val value = field.get(instance)
      return if (!fieldType.isInstance(value)) null else fieldType.cast(value)

    //                                                                           =========
    private static final DuplicateHostDbm _instance = new DuplicateHostDbm();

    private DuplicateHostDbm() {
    }

    public static DuplicateHostDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

    //                                                                           =========
    private static final RelatedQueryDbm _instance = new RelatedQueryDbm();

    private RelatedQueryDbm() {
    }

    public static RelatedQueryDbm getInstance() {
        return _instance;
    }

    // ===================================================================================

    //                                                                           =========
    private static final RoleTypeDbm _instance = new RoleTypeDbm();

    private RoleTypeDbm() {
    }

    public static RoleTypeDbm getInstance() {
        return _instance;
    }

    // ===================================================================================