TODO docstring.

def payzen_form(payment_request, auto_submit=False):
    """TODO docstring."""
    if auto_submit:
        template_used = "django_payzen/auto_submit_form.html"
    else:
        template_used = "django_payzen/form.html"
    payment_request.update()
    t = template.loader.get_template(template_used)
    return t.render({
        "form": forms.PaymentRequestForm(instance=payment_request),
        "payzen_submit_url": app_settings.PAYZEN_REQUEST_URL
    })