suite.addTest(testsForConcurrentSkipListSetNatural());
    suite.addTest(testsForConcurrentSkipListSetWithComparator());

    return suite;
  }

  protected Collection<Method> suppressForEmptySet() {
    return emptySet();
  }

  protected Collection<Method> suppressForSingletonSet() {
    return emptySet();
  }

  protected Collection<Method> suppressForHashSet() {
    return emptySet();
  }

    return suite;
  }

  protected Collection<Method> suppressForCheckedNavigableSet() {
    return emptySet();
  }

  protected Collection<Method> suppressForEmptySet() {
    return emptySet();
  }

  protected Collection<Method> suppressForEmptyNavigableSet() {
    return emptySet();
  }

  protected Collection<Method> suppressForEmptySortedSet() {