anchor.diff:      (is (eq a (car (object-parents c))))
       (is (eq b (car (object-parents d))))
       (is (eq c (cadr (object-parents d)))))
  -  (signals object-hierarchy-error
  +  (signals object-precedence-error
       (with-object-hierarchy (a (b a) (c b) (d a c))
         (declare (ignore d)))))
   
  
positive.code:   (with-object-hierarchy (a b (c a))
      (push b (object-parents a))
      (is (equal (list c a b =standard-object= =t=)
                 (object-hierarchy-list c)))
      (setf (object-parents c) (list b))
      (is (equal (list c b =standard-object= =t=)
                 (object-hierarchy-list c)))
      (push c (object-parents a))
      (is (equal (list a c b =standard-object= =t=)
                 (object-hierarchy-list a)))))
  
  (test cache-update-moderate
    (with-object-hierarchy (a (b a) (c a) (d b) (e c) x)
      (push x (object-parents a))
      (is (equal (list a x =standard-object= =t=)
                 (object-hierarchy-list a)))
      (is (equal (list b a x =standard-object= =t=)
                 (object-hierarchy-list b)))
      (is (equal (list c a x =standard-object= =t=)
                 (object-hierarchy-list c)))
      (is (equal (list d b a x =standard-object= =t=)
                 (object-hierarchy-list d)))
      (is (equal (list e c a x =standard-object= =t=)
                 (object-hierarchy-list e)))))
  
  (test cache-update-extensive
    (with-object-hierarchy (a b c d e f g h)
  
negative.code: ;;; how to test what this actually SHOULD do
  (test std-tie-breaker-rule)
  
  (test object-precedence-list
    (with-object-hierarchy (parent (child parent))
      (is (equal (list child parent =standard-object= =t=)
                 (object-precedence-list child))))
    (with-object-hierarchy (a (b a) (c b))
      (is (equal (list c b a =standard-object= =t=)
                 (object-precedence-list c))))
    (with-object-hierarchy (a b (c a) (d a) (e b c) (f d) (g c f) (h g e))
      (is (equal (list h g e b c f d a =standard-object= =t=)
                 (object-precedence-list h)))))
  
  ;;; Testing the utility...
  (in-suite objects)
  