final Map<Path, Holder> modelByPath = new ConcurrentHashMap<>();

    final Map<GAKey, Holder> modelByGA = new ConcurrentHashMap<>();

    public static class Holder {
        private volatile boolean set;
        private volatile Model model;

        Holder() {}

        Holder(Model model) {
            this.model = Objects.requireNonNull(model);

  }

  public void testGetAndAdd() {
    Count holder = new Count(20);
    assertEquals(20, holder.get());
    holder.add(1);
    assertEquals(21, holder.get());
  }

  public void testAddAndGet() {
    Count holder = new Count(20);
    assertEquals(21, holder.addAndGet(1));
  }

  public void testGetAndSet() {
    Count holder = new Count(10);
    assertEquals(10, holder.getAndSet(20));
    assertEquals(20, holder.get());

  }

  public void testGetAndAdd() {
    Count holder = new Count(20);
    assertEquals(20, holder.get());
    holder.add(1);
    assertEquals(21, holder.get());
  }

  public void testAddAndGet() {
    Count holder = new Count(20);
    assertEquals(21, holder.addAndGet(1));
  }

  public void testGetAndSet() {
    Count holder = new Count(10);
    assertEquals(10, holder.getAndSet(20));
    assertEquals(20, holder.get());

        DirContextHolder holder = contextLocal.get();
        if (holder != null) {
            holder.inc();
            return holder;
        }
        final Hashtable<String, String> env = envSupplier.get();
        try {
            holder = new DirContextHolder(new InitialDirContext(env));
            contextLocal.set(holder);
            return holder;
        } catch (final NamingException e) {

   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its
   contributors may be used to endorse or promote products derived from
   this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

   * it can fail here.
   */
  public void testAnonymous() {
    final AtomicReference<String> holder = new AtomicReference<>();
    final AtomicInteger deliveries = new AtomicInteger();
    EventBus bus = new EventBus();
    bus.register(
        new Object() {
          @Subscribe
          public void accept(String str) {
            holder.set(str);
            deliveries.incrementAndGet();
          }
        });

Copyright <YEAR> <COPYRIGHT HOLDER>

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the

    ImmutableMultimap.Builder<String, Integer> builder = new Builder<>();
    final StringHolder holder = new StringHolder();
    holder.string = "one";
    Entry<String, Integer> entry =
        new AbstractMapEntry<String, Integer>() {
          @Override
          public String getKey() {
            return holder.string;
          }

          @Override
          public Integer getValue() {

    ImmutableMultimap.Builder<String, Integer> builder = new Builder<>();
    final StringHolder holder = new StringHolder();
    holder.string = "one";
    Entry<String, Integer> entry =
        new AbstractMapEntry<String, Integer>() {
          @Override
          public String getKey() {
            return holder.string;
          }

          @Override
          public Integer getValue() {

          try {
            // The cast is safe because tryAdvance puts a T into `holder`.
            action.accept(function.apply(uncheckedCastNullableTToT(holder), index++));
            return true;
          } finally {
            holder = null;
          }
        }
        return false;
      }

      @Override
      Splitr createSplit(Spliterator<T> from, long i) {