this.itemReporter = checkNotNull(itemReporter);
  }

  // TODO(cpovirk): should we reject null items, since the tests already check null automatically?
  @CanIgnoreReturnValue
  public RelationshipTester<T> addRelatedGroup(Iterable<? extends T> group) {
    groups.add(ImmutableList.copyOf(group));
    return this;
  }

  public void test() {
    for (int groupNumber = 0; groupNumber < groups.size(); groupNumber++) {

    addEquivalenceGroup(Lists.asList(first, rest));
    return this;
  }

  @CanIgnoreReturnValue
  public EquivalenceTester<T> addEquivalenceGroup(Iterable<T> group) {
    delegate.addRelatedGroup(group);
    items.addAll(ImmutableList.copyOf(group));
    return this;
  }

  /** Run tests on equivalence methods, throwing a failure on an invalid test */
  @CanIgnoreReturnValue

        new RelationshipTester<>(
            Equivalence.equals(), "Object#equals", "Object#hashCode", itemReporter);
    for (List<Object> group : equalityGroups) {
      delegate.addRelatedGroup(group);
    }
    for (int run = 0; run < REPETITIONS; run++) {
      testItems();
      delegate.test();
    }
    return this;
  }

  private void testItems() {

    this.itemReporter = checkNotNull(itemReporter);
  }

  // TODO(cpovirk): should we reject null items, since the tests already check null automatically?
  @CanIgnoreReturnValue
  public RelationshipTester<T> addRelatedGroup(Iterable<? extends T> group) {
    groups.add(ImmutableList.copyOf(group));
    return this;
  }

  public void test() {
    for (int groupNumber = 0; groupNumber < groups.size(); groupNumber++) {

        new RelationshipTester<>(
            Equivalence.equals(), "Object#equals", "Object#hashCode", itemReporter);
    for (List<Object> group : equalityGroups) {
      delegate.addRelatedGroup(group);
    }
    for (int run = 0; run < REPETITIONS; run++) {
      testItems();
      delegate.test();
    }
    return this;
  }

  private void testItems() {