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
  public EqualsTester testEquals() {
    RelationshipTester<Object> delegate =
        new RelationshipTester<>(

        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
  public EqualsTester testEquals() {
    RelationshipTester<Object> delegate =
        new RelationshipTester<>(