}

  private Item<T> getItem(int groupNumber, int itemNumber) {
    return new Item<>(groups.get(groupNumber).get(itemNumber), groupNumber, itemNumber);
  }

  static final class Item<T> {
    final T value;
    final int groupNumber;
    final int itemNumber;

    Item(T value, int groupNumber, int itemNumber) {
      this.value = value;
      this.groupNumber = groupNumber;
      this.itemNumber = itemNumber;

  }

  private Item<T> getItem(int groupNumber, int itemNumber) {
    return new Item<>(groups.get(groupNumber).get(itemNumber), groupNumber, itemNumber);
  }

  static final class Item<T> {
    final T value;
    final int groupNumber;
    final int itemNumber;

    Item(T value, int groupNumber, int itemNumber) {
      this.value = value;
      this.groupNumber = groupNumber;
      this.itemNumber = itemNumber;

    argGroups.add(ImmutableList.of(args, equalArgs));
    EqualsTester tester =
        new EqualsTester(
            /* itemReporter= */ item -> {
              List<Object> factoryArgs = argGroups.get(item.groupNumber).get(item.itemNumber);
              return factory.getName()
                  + "("
                  + Joiner.on(", ").useForNull("null").join(factoryArgs)
                  + ")";
            });

    argGroups.add(ImmutableList.of(args, equalArgs));
    EqualsTester tester =
        new EqualsTester(
            /* itemReporter= */ item -> {
              List<Object> factoryArgs = argGroups.get(item.groupNumber).get(item.itemNumber);
              return factory.getName()
                  + "("
                  + Joiner.on(", ").useForNull("null").join(factoryArgs)
                  + ")";
            });