#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""http://www.testingperspective.com/wiki/doku.php/collaboration/chetan/designpatternsinpython/chain-of-responsibilitypattern"""

class Handler:
    def __init__(self,successor):
        self._successor = successor;
    def handle(self,request):
        i = self._handle(request)
        if  not i:
            self._successor.handle(request)
    def _handle(self, request):
        raise NotImplementedError('Must provide implementation in subclass.')


class ConcreteHandler1(Handler):

    def _handle(self, request):
        if 0 < request