private void checkFalse(Object x, Object y) {
   assertFalse(equality.equivalent(x, y));
   assertFalse(equality.equivalent(y, x));
   try {
     equality.assertEquivalent(x, y, new LinkedList<String>());
     throw new RuntimeException();
   } catch (AssertionError e) {
   }
   try {
     equality.assertEquivalent(y, x, new LinkedList<String>());
     throw new RuntimeException();
   } catch (AssertionError e) {
   }
 }
 private void checkTrue(Object x, Object y) {
   assertTrue(equality.equivalent(x, y));
   assertTrue(equality.equivalent(y, x));
   equality.assertEquivalent(x, y, new LinkedList<String>());
   equality.assertEquivalent(y, x, new LinkedList<String>());
 }