'If a model\'s ManyToManyField has blank=True and is saved with no data, a queryset is returned.'

def test_empty_queryset_return(self):

    option = ChoiceOptionModel.objects.create(name=u'default')
    form = OptionalMultiChoiceModelForm({u'multi_choice_optional': u'', u'multi_choice': [option.pk]})
    self.assertTrue(form.is_valid())
    self.assertIsInstance(form.cleaned_data[u'multi_choice_optional'], models.query.QuerySet)
    self.assertIsInstance(form.cleaned_data[u'multi_choice'], models.query.QuerySet)
