List<?> exp = copyToList(expected);
    List<?> act = copyToList(actual);
    String actString = act.toString();

    // Of course we could take pains to give the complete description of the
    // problem on any failure.

    // Yeah it's n^2.
    for (Object object : exp) {
      if (!act.remove(object)) {
        fail(
            "did not contain expected element "

  }

  /**
   * Creates an {@code EnumSet} consisting of all enum values that are not in the specified
   * collection. This is equivalent to {@link EnumSet#complementOf}, but can act on any input
   * collection, as long as the elements are of enum type.
   *
   * @param collection the collection whose complement should be stored in the {@code EnumSet}
   * @param type the type of the elements in the set