def METHOD_NAME(registration, notify_user=True, diff=None, old_price=None):
    if notify_user:
        _notify_registration(registration, 'registration_modification_to_registrant.html',
                             diff=diff, old_price=old_price)
    if registration.registration_form.manager_notifications_enabled:
        _notify_registration(registration, 'registration_modification_to_managers.html', to_managers=True,
                             diff=diff, old_price=old_price)