* Returns a {@link Collection} of all the permutations of the specified {@link Iterable}.
   *
   * <p><i>Notes:</i> This is an implementation of the algorithm for Lexicographical Permutations
   * Generation, described in Knuth's "The Art of Computer Programming", Volume 4, Chapter 7,
   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the

      List<T> expectedPermutation, Iterator<List<T>> permutations) {
    assertTrue("Expected another permutation, but there was none.", permutations.hasNext());
    assertEquals(expectedPermutation, permutations.next());
  }

  private <T> void assertNoMorePermutations(Iterator<List<T>> permutations) {
    assertFalse("Expected no more permutations, but there was one.", permutations.hasNext());
    try {
      permutations.next();

    }
  }

  public void testRemoveAt_exhaustive() {
    int size = reduceExponentIfGwt(8);
    List<Integer> expected = createOrderedList(size);
    for (Collection<Integer> perm : Collections2.permutations(expected)) {
      for (int i = 0; i < perm.size(); i++) {
        MinMaxPriorityQueue<Integer> q = MinMaxPriorityQueue.create(perm);
        q.removeAt(i);
        assertIntactUsingStartedWith(perm, q);
      }

  /** Non-NPE RuntimeException. */
  public static class FooException extends RuntimeException {
    private static final long serialVersionUID = 1L;
  }

  /**
   * Class for testing all permutations of static/non-static one-argument methods using
   * methodParameter().
   */
  @SuppressWarnings("unused") // used by reflection
  public static class OneArg {