(require-extension coops)

(define (bar)
  (print "bar v1"))

(bar)

(define (bar)
  (print "bar v2"))

(bar)


(define-class <a> ())

(define a (make <a>))

(define-method (foo (a <a>))
  (print "foo v1 on " a))

(foo a)

(define-method (foo (a <a>))
  (print "foo v2 on " a))

(foo a)

;; Output:
;; bar v1
;; bar v2
;; foo v1 on #<coops instance of `<a>'>
;; foo v1 on #<coops instance of `<a>'> <-- nothing changed