return False

    def _refresh(self):

        ''' Refreshes the underlying invoice and cart objects. '''

        self.invoice.refresh_from_db()

from registrasion import models as rego

from django.core.exceptions import ObjectDoesNotExist

class TestingCartController(CartController):

        self.validate_allowed_to_pay()

        ''' Adds a payment '''

            invoice=self.invoice,

            reference=reference,

            amount=amount,

from registrasion import models as rego

from registrasion.controllers import discount

from controller_helpers import TestingCartController

from test_cart import RegistrationCartTestCase

    def test_cannot_generate_blank_invoice(self):

        current_cart = TestingCartController.for_user(self.USER_1)

        with self.assertRaises(ValidationError):

    def test_cannot_pay_implicitly_void_invoice(self):

        cart = TestingCartController.for_user(self.USER_1)

        with self.assertRaises(ValidationError):

            invoice.validate_allowed_to_pay()

    # TODO: test partially paid invoice cannot be void until payments

    # are refunded

from django.utils.crypto import get_random_string

def generate_access_code():

    ''' Generates an access code for users' payments as well as their

    fulfilment code for check-in.

    if not current_invoice.can_view(

            user=request.user,

            access_code=access_code,

        raise Http404()

    data = {