Other Methods

reset: set all Vars to their default value for the given state (including substates).
get_value: returns the value of a Var without tracking changes to it. This is useful for serialization where the tracking wrapper is considered unserializable.
dict: returns all state Vars (and substates) as a dictionary. This is used internally when a page is first loaded and needs to be "hydrated" and sent to the client.

Special Attributes

dirty_vars: a set of all Var names that have been modified since the last time the state was sent to the client. This is used internally to determine which Vars need to be sent to the client after processing an event.