anchor.diff:          :cl-test-more))
   (in-package :cl21-test.sequence)
   
  -(plan 290)
  +(plan 295)
   
   (is (take 3 '(1 3 5 6 7 8))
       '(1 3 5)
  
positive.code:     (is (coerce seq 'list) '(0 10 1 2 3) "pushnew"))
    (let ((poped (pop seq)))
      (is poped 0 "pop")
      (is (coerce seq 'list) '(10 1 2 3) "pop")))
  
  (let ((seq (make-array 3
                         :initial-contents
  
negative.code:     (is-type pushed 'my-list "push")
      (is (coerce pushed 'list) '(10 1 2 3) "push")
      (is (coerce seq 'list) '(10 1 2 3) "push"))
    (let ((seq (make-my-list (list 1))))
      (push 'a (elt seq 0))
      (is (coerce seq 'list) '((a 1)) "push"))
    (let ((seq (list (list) (list) (list)))
          (index 0))
      (push 'a (elt seq (incf index)))
      (is seq '(() (a) ()) "push")
      (is index 1 "push"))
    (let ((pushed-new (pushnew 0 seq)))
      (is-type pushed-new 'my-list "pushnew")
      (is (coerce pushed-new 'list) '(0 10 1 2 3) "pushnew")
  