class Hooker(Delegator):

    def __init__(self):
        Delegator.__init__(self)


class Interceptor(Delegator):

    def __init__(self):
        Delegator.__init__(self)

def fcn():
    print "Fcn at base"

if __name__ == "__main__":
    bottom = Hooker()
    bottom.setdelegate(fcn)
    middle = Hooker()
    middle.setdelegate(bottom)
    top = Interceptor()
    top.setdelegate(middle)
    print "top.delegate: ", top.delegate
    print "calling top(): ",
    top()