def test_empty(self): iv = IntervalTree() self.assertEqual([], iv.find(100, 300)) self.assertEqual([], iv.after(100)) self.assertEqual([], iv.before(100)) self.assertEqual([], iv.after_interval(100)) self.assertEqual([], iv.before_interval(100)) self.assertEqual([], iv.upstream_of_interval(100)) self.assertEqual([], iv.downstream_of_interval(100)) self.assertEqual(None, iv.traverse(lambda x: x.append(1)))