* {@link #valueField} of {@code future}.
   */
  static boolean casValue(AbstractFutureState<?> future, @Nullable Object expect, Object update) {
    return ATOMIC_HELPER.casValue(future, expect, update);
  }

  /** Returns the value of the future, using a volatile read. */
  final @Nullable Object value() {
    return valueField;
  }

  /** Returns the head of the listener stack, using a volatile read. */

        thumbnailManager.add(generator);

        Map<String, Object> docMap = new HashMap<>();
        docMap.put("_id", "docid1");

        // Fill the queue
        thumbnailManager.offer(docMap);

        // Try to add another - should succeed (warning logged but still returns true)
        Map<String, Object> docMap2 = new HashMap<>();
        docMap2.put("_id", "docid2");

    }
    return hash;
  }

  @Override
  public boolean equals(@Nullable Object obj) {
    if (obj instanceof PairwiseEquivalence) {
      @SuppressWarnings("unchecked")
      PairwiseEquivalence<Object, Object> that = (PairwiseEquivalence<Object, Object>) obj;
      return this.elementEquivalence.equals(that.elementEquivalence);
    }

    return false;
  }

  @Override

    /**
     * Method setFileComment.
     *
     * @param fileComment a fileComment object.
     */
    public void setFileComment(String fileComment) {
        delegate.setFileComment(fileComment);
    }

    /**
     * Method write.
     *
     * @param writer a writer object.
     * @param persistedToolchains a persistedToolchains object.
     * @throws IOException java.io.IOException if any.
     */

    }

    @Override
    protected String getItemEndpointSuffix() {
        return ITEM_ENDPOINT_SUFFIX;
    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);

    }

    @Override
    protected String getItemEndpointSuffix() {
        return ITEM_ENDPOINT_SUFFIX;
    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);
        requestBody.put("query", "query" + id);

    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);
        requestBody.put("value", Integer.valueOf(id).toString());
        return requestBody;
    }

    @Override
    protected Map<String, Object> getUpdateMap() {

    }

    @Override
    protected String getItemEndpointSuffix() {
        return ITEM_ENDPOINT_SUFFIX;
    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);
        requestBody.put("replacement", "replacement" + id);

    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);
        requestBody.put("output", "output");
        return requestBody;
    }

    @Override
    protected Map<String, Object> getUpdateMap() {

    SettableFuture<Object> future2 = SettableFuture.create();

    // A more organic OOM from a toString implementation
    Object object =
        new Object() {
          @Override
          public String toString() {
            return new String(new char[50_000]);
          }
        };
    List<Object> list = Collections.singletonList(object);
    for (int i = 0; i < 10; i++) {