Collections.shuffle(hashCodes, random);
    HashCode hashCode2 = Hashing.combineOrdered(hashCodes);

    assertFalse(hashCode1.equals(hashCode2));
  }

  public void testCombineUnordered_empty() {
    assertThrows(
        IllegalArgumentException.class,
        () -> Hashing.combineUnordered(Collections.<HashCode>emptySet()));
  }

  public void testCombineUnordered_differentBitLengths() {