'All unique items from either list.'

def test_intersect_items(self):

    listA = [1, 2, 3, 4, 5, 8, 9]
    listB = [1, 2, 3, 4, 5, 6, 7]
    want = [1, 2, 3, 4, 5]
    got = _intersect_items(listA, listB)
    self.assertEqual(want, got)
    new_tags = ['one', 'two']
    existing_tags = ['two']
    want = ['two']
    got = _intersect_items(existing_tags, new_tags)
    self.assertEqual(want, got)
