def process_response(self, request, response, spider):
    if 'dont_merge_cookies' in request.meta:
        return response

    # extract cookies from Set-Cookie and drop invalid/expired cookies
    cookiejarkey = request.meta.get("cookiejar")
    jar = self.jars[cookiejarkey]
    jar.extract_cookies(response, request)
    spider.jars = self.jars

    cls = type(response)
    def _get_cookies(self, jars):
        return {i.name: i.value for i in list(jars[cookiejarkey])}
    if not hasattr(cls, 'cookies'):
        cls._get_cookies = lambda self: None
        cls.cookies = property(lambda self: self._get_cookies())
    response._get_cookies = partial(_get_cookies, response, jars=self.jars)

    self._debug_set_cookie(response, spider)
    return response