public TestSuite createTestSuite() {
    checkCanCreate();

    logger.fine(" Testing: " + name);
    logger.fine("Features: " + formatFeatureSet(features));

    addImpliedFeatures(features);

    logger.fine("Expanded: " + formatFeatureSet(features));

    @SuppressWarnings("rawtypes") // class literals
    List<Class<? extends AbstractTester>> testers = getTesters();

    features.removeAll(sizesToTest);

    addImpliedFeatures(sizesToTest);
    sizesToTest.retainAll(asList(CollectionSize.ZERO, CollectionSize.ONE, CollectionSize.SEVERAL));

    logger.fine("   Sizes: " + formatFeatureSet(sizesToTest));

    if (sizesToTest.isEmpty()) {
      throw new IllegalStateException(
          name
              + ": no CollectionSizes specified (check the argument to "