'If request.session was modified, or if the configuration is to save the
session every time, save the changes and set a session cookie.'

def process_response(self, request, response):

    try:
        accessed = request.session.accessed
        modified = request.session.modified
    except AttributeError:
        pass
    else:
        if accessed:
            patch_vary_headers(response, ('Cookie',))
        if (modified or settings.SESSION_SAVE_EVERY_REQUEST):
            if request.session.get_expire_at_browser_close():
                max_age = None
                expires = None
            else:
                max_age = request.session.get_expiry_age()
                expires_time = (time.time() + max_age)
                expires = cookie_date(expires_time)
            if (response.status_code != 500):
                request.session.save()
                response.set_cookie(settings.SESSION_COOKIE_NAME, request.session.session_key, max_age=max_age, expires=expires, domain=settings.SESSION_COOKIE_DOMAIN, path=settings.SESSION_COOKIE_PATH, secure=(settings.SESSION_COOKIE_SECURE or None), httponly=(settings.SESSION_COOKIE_HTTPONLY or None))
    return response
