*
   * @param future The future attach the callback to.
   * @param callback The callback to invoke when {@code future} is completed.
   * @param executor The executor to run {@code callback} when the future completes.
   * @since 10.0
   */
  public static <V extends @Nullable Object> void addCallback(
      ListenableFuture<V> future, FutureCallback<? super V> callback, Executor executor) {

## Version 3.7.0

_2017-04-15_

 *  **OkHttp no longer recovers from TLS handshake failures by attempting a TLSv1 connection.**
    The fallback was necessary for servers that implemented version negotiation incorrectly. Now
    that 99.99% of servers do it right this fallback is obsolete.
 *  Fix: Do not honor cookies set on a public domain. Previously a malicious site could inject

		return policies, nil
	}

	if userPolicyPresent {
		// if user mapping present and no group policies found
		// rely on user policy for access, instead of fallback.
		return nil, nil
	}

	var mu sync.Mutex

	// no mappings found, fallback for all groups.
	g := errgroup.WithNErrs(len(groups)).WithConcurrency(10) // load like 10 groups at a time.

	for index := range groups {
		g.Go(func() error {

	{"oooooooooooooooooooooo", "r", -1},
	{"oxoxoxoxoxoxoxoxoxoxoxoy", "oy", 22},
	{"oxoxoxoxoxoxoxoxoxoxoxox", "oy", -1},
	// test fallback to Rabin-Karp.
	{"000000000000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000001", 5},
	// test fallback to IndexRune
	{"oxoxoxoxoxoxoxoxoxoxox☺", "☺", 22},
	// invalid UTF-8 byte sequence (must be longer than bytealg.MaxBruteForce to

            return result;
        } catch (Exception e) {
            log.warn("Failed to create fresh context, using singleton", e);
            try {
                // Fallback to singleton with fresh auth
                NtlmPasswordAuthentication auth =
                        new NtlmPasswordAuthentication(SingletonContext.getInstance(), WORKGROUP, USERNAME, PASSWORD);

		case isSysErrInvalidArg(err):
			st, _ := Lstat(filePath)
			if st != nil && st.IsDir() {
				// Linux returns InvalidArg for directory O_DIRECT
				// we need to keep this fallback code to return correct
				// errors upwards.
				return nil, dmTime, errFileNotFound
			}
			return nil, dmTime, errUnsupportedDisk
		}
		return nil, dmTime, err
	}
	defer f.Close()

        KeyMatchCQ cq = new KeyMatchCQ();
        queryLambda.callback(cq);
        final Collection<FilterFunctionBuilder> list = new ArrayList<>();
        if (functionsLambda != null) {
            functionsLambda.callback((cqLambda, scoreFunctionBuilder) -> {
                KeyMatchCQ cf = new KeyMatchCQ();
                cqLambda.callback(cf);

        if (queryLambda != null) {
            queryLambda.callback(cq);
        }
        FilterAggregationBuilder builder = regFilterA(name, cq.getQuery());
        if (opLambda != null) {
            opLambda.callback(builder);
        }
        if (aggsLambda != null) {
            DataConfigCA ca = new DataConfigCA();
            aggsLambda.callback(ca);

        if (queryLambda != null) {
            queryLambda.callback(cq);
        }
        FilterAggregationBuilder builder = regFilterA(name, cq.getQuery());
        if (opLambda != null) {
            opLambda.callback(builder);
        }
        if (aggsLambda != null) {
            AccessTokenCA ca = new AccessTokenCA();
            aggsLambda.callback(ca);

        if (queryLambda != null) {
            queryLambda.callback(cq);
        }
        FilterAggregationBuilder builder = regFilterA(name, cq.getQuery());
        if (opLambda != null) {
            opLambda.callback(builder);
        }
        if (aggsLambda != null) {
            JobLogCA ca = new JobLogCA();
            aggsLambda.callback(ca);
            ca.getAggregationBuilderList().forEach(builder::subAggregation);