def invalid_tree(invalid_channel, invalid_topic, invalid_document):
invalid_topic.add_child(invalid_document)
invalid_channel.add_child(invalid_topic)
return ChannelManager(invalid_channel)
def invalid_tree_2(channel, topic, invalid_document):
channel_copy = copy.deepcopy(channel)
topic_copy = copy.deepcopy(topic)
topic_copy.add_child(invalid_document)
channel_copy.add_child(topic_copy)
return ChannelManager(channel_copy)
def tree(channel, topic, document):
topic.add_child(document)
channel.add_child(topic)
return ChannelManager(channel)