def test_breadth_first_search(): section = ExperimentSection(make_tree(['session', 'block', 'trial'], {}), ChainMap()) section[1][2].data['foo'] = True key = lambda node: node.data.get('foo', False) search_result = section.breadth_first_search(key) assert search_result == [section, section[1], section[1][2]] assert section.breadth_first_search(lambda node: False) == []