@Override
    protected Set<String> create(String[] elements) {
      return ImmutableSet.of(elements[0], elements[0]);
    }
  }

  public static class ImmutableSortedSetCopyOfGenerator extends TestStringSortedSetGenerator {
    @Override
    protected SortedSet<String> create(String[] elements) {
      return ImmutableSortedSet.copyOf(elements);
    }
  }

    @Override
    protected Set<String> create(String[] elements) {
      return ImmutableSet.of(elements[0], elements[0]);
    }
  }

  public static class ImmutableSortedSetCopyOfGenerator extends TestStringSortedSetGenerator {
    @Override
    protected SortedSet<String> create(String[] elements) {
      return ImmutableSortedSet.copyOf(elements);
    }
  }