Function subscribe

app/src/utils/pullModelManager.ts:140–148

(listener: Listener)

};

const subscribe = (listener: Listener): (() => void) => {
  listeners.push(listener);
  return () => { // Return an unsubscribe function
    const index = listeners.indexOf(listener);
    if (index > -1) {
      listeners.splice(index, 1);
    }
  };
};

const getInitialState = (): PullState => {
  return state;