Subscription manager for object state changes.
Reuses ProxyReference and SubscriptionManager from helpers.ts. The value (usually the owner object itself) is set once in the constructor and never becomes undefined, so every notify() is guaranteed to notify all subscribers with that value.
Used to implement GateInterface.onStateChange().
Subscription manager for object state changes.
Reuses ProxyReference and SubscriptionManager from helpers.ts. The value (usually the owner object itself) is set once in the constructor and never becomes undefined, so every notify() is guaranteed to notify all subscribers with that value.
Used to implement GateInterface.onStateChange().