features.addAll(parentBuilder.getFeatures());

    return subSuiteUsing(new DescendingTestMapGenerator<K, V>(delegate))
        .named(parentBuilder.getName() + " descending")
        .withFeatures(features)
        .suppressing(parentBuilder.getSuppressedTests())
        .createTestSuite();
  }

  NavigableMapTestSuiteBuilder<K, V> subSuiteUsing(TestSortedMapGenerator<K, V> generator) {
    return using(generator);
  }

    features.addAll(parentBuilder.getFeatures());

    return subSuiteUsing(new DescendingTestMapGenerator<K, V>(delegate))
        .named(parentBuilder.getName() + " descending")
        .withFeatures(features)
        .suppressing(parentBuilder.getSuppressedTests())
        .createTestSuite();
  }

  NavigableMapTestSuiteBuilder<K, V> subSuiteUsing(TestSortedMapGenerator<K, V> generator) {
    return using(generator);
  }

    List<Class<? extends AbstractTester>> testers = copyToList(super.getTesters());
    testers.addAll(ConcurrentMapTestSuiteBuilder.TESTERS);
    return testers;
  }

  @Override
  NavigableMapTestSuiteBuilder<K, V> subSuiteUsing(TestSortedMapGenerator<K, V> generator) {
    return using(generator);
  }

    List<Class<? extends AbstractTester>> testers = copyToList(super.getTesters());
    testers.addAll(ConcurrentMapTestSuiteBuilder.TESTERS);
    return testers;
  }

  @Override
  NavigableMapTestSuiteBuilder<K, V> subSuiteUsing(TestSortedMapGenerator<K, V> generator) {
    return using(generator);
  }