for (int i = 0; i < equalityGroup.length; i++) {
      Object element = equalityGroup[i];
      if (element == null) {
        throw new NullPointerException("at index " + i);
      }
      list.add(element);
    }
    equalityGroups.add(list);
    return this;
  }

  /** Run tests on equals method, throwing a failure on an invalid test */
  @CanIgnoreReturnValue

   *
   * <p>Note: this method is idempotent and safe to call from any thread
   */
  public void dispatch() {
    // iterate by index to avoid concurrent modification exceptions
    for (int i = 0; i < listeners.size(); i++) {
      listeners.get(i).dispatch();
    }
  }

  /**