A node can be thought of as simply a (public) history - that is, the list of actions taken to reach that node. It could be quite Pythonic to be able to manipulate nodes as histories in this way.

• Be able to access the list of actions leading to the node - e.g. as Node.history property?
• define operator + such that Node + Action -> child node, assuming Action is an action at Node. Alternatively, Node + str -> child node, if the text string is the label of an action at the Node.