assertTrue(
            comparator + ".compare(" + greater + ", " + t + ")",
            comparator.compare(greater, t) > 0);
      }
    }
  }

  @SuppressWarnings({"SelfComparison", "SelfEquals"})
  public static <T extends Comparable<? super T>> void testCompareToAndEquals(
      List<T> valuesInExpectedOrder) {
    // This does an O(n^2) test of all pairs of values in both orders

    assertTrue(ArbitraryInstances.get(Equivalence.class).equivalent(1, 1));
    assertFalse(ArbitraryInstances.get(Equivalence.class).equivalent(1, 2));
  }

  @SuppressWarnings("SelfComparison")
  public void testGet_comparable() {
    @SuppressWarnings("unchecked") // The null value can compare with any Object
    Comparable<Object> comparable = ArbitraryInstances.get(Comparable.class);

    assertTrue(ArbitraryInstances.get(Equivalence.class).equivalent(1, 1));
    assertFalse(ArbitraryInstances.get(Equivalence.class).equivalent(1, 2));
  }

  @SuppressWarnings("SelfComparison")
  public void testGet_comparable() {
    @SuppressWarnings("unchecked") // The null value can compare with any Object
    Comparable<Object> comparable = ArbitraryInstances.get(Comparable.class);