'Tags that do not start with the namespace will be added with the
namespace tacked on.'

def test_add_ns(self):

    apple = self.food_model.objects.create(name='apple')
    tags = ['foo', 'bar', 'baz']
    apple.tags.add_ns('a:', *tags)
    self.assert_tags_equal(apple.tags.all(), [('a:%s' % t) for t in tags])
