def METHOD_NAME(self):
    self.assertEqual(utils.find_subtree(self.torrent, ('bar2', 'zap1', 'xxx')), None)
    self.assertEqual(utils.find_subtree(self.torrent, ('bar2', 'zap2', 'xxx')), None)
    self.assertEqual(utils.find_subtree(self.torrent, ('bar2', 'zap2', 'xxx', 'yyy', 'zzz')), None)
    self.assertEqual(utils.find_subtree(self.torrent, ('bar1', 'baz2', 'bat1', 'bax1', 'xxx')), None)