django multiple forms on page causes management form error code example

Example: multiple form in one class djanog

class MultipleFormsDemoView(MultiFormsView):
    template_name = "pages/cbv_multiple_forms.html"
    form_classes = {'contact': ContactForm,
                    'subscription': SubscriptionForm,
                    }

    success_urls = {
        'contact': reverse_lazy('contact-form-redirect'),
        'subscription': reverse_lazy('submission-form-redirect'),
    }

    def contact_form_valid(self, form):
        'contact form processing goes in here'

    def subscription_form_valid(self, form):
        'subscription form processing goes in here'