'Make sure that creating a new document doesn\'t change the
category of all the other documents.'

def test_new_doc_does_not_update_categories(self):

    d1 = DocumentFactory(category=20)
    assert d1.pk
    d2 = DocumentFactory.build(category=30)
    assert (not d2.pk)
    d2._clean_category()
    d1prime = Document.objects.get(pk=d1.pk)
    eq_(20, d1prime.category)
