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);

    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) {

                Model model = findRawModel(from, gId, aId);
                if (model != null) {
                    context.modelByGA.put(new GAKey(gId, aId), new Holder(model));
                    context.modelByPath.put(model.getPomPath(), new Holder(model));
                }
                return model;
            }

            @Override
            public Model getRawModel(Path from, Path path) {

                      holder.count++;
                      return null;
                    }
                  },
                  directExecutor());
        }
      }
      settableFuture.set(null);
      completeLengthChecks = allAsList(lengthChecks).get();
    } finally {
      service.shutdown();
    }
    assertThat(holder.count).isEqualTo(ITERATION_COUNT);

          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) {

                      holder.count++;
                      return null;
                    }
                  },
                  directExecutor());
        }
      }
      settableFuture.set(null);
      completeLengthChecks = allAsList(lengthChecks).get();
    } finally {
      service.shutdown();
    }
    assertThat(holder.count).isEqualTo(ITERATION_COUNT);

  @GwtIncompatible // SerializableTester
  public void testSerializationIndirectSelfReference() {
    Multiset<MultisetHolder> multiset = HashMultiset.create();
    MultisetHolder holder = new MultisetHolder(multiset);
    multiset.add(holder, 2);
    Multiset<MultisetHolder> copy = SerializableTester.reserialize(multiset);
    assertEquals(2, copy.size());
    assertSame(copy, copy.iterator().next().member);
  }

  /*

  @GwtIncompatible // SerializableTester
  public void testSerializationIndirectSelfReference() {
    Multiset<MultisetHolder> multiset = HashMultiset.create();
    MultisetHolder holder = new MultisetHolder(multiset);
    multiset.add(holder, 2);
    Multiset<MultisetHolder> copy = SerializableTester.reserialize(multiset);
    assertEquals(2, copy.size());
    assertSame(copy, copy.iterator().next().member);
  }

  /*