pubsub.subscribe('myTopic', (event, ...args) => {
    // do something here.
});
 
pubsub.once('anotherTopic', someCallback);

// in any process
pubsub.publish('myTopic', 'some arguments');

// in any process
pubsub.unsubscribe('myTopic', someCallback);
pubsub.unsubscribe('myTopic');
 
pubsub.clearAllSubscriptions();

pubsub.subscribe('a', myFunc1);
pubsub.subscribe('a.b', myFunc2);
pubsub.subscribe('a.b.c', myFunc3);
 
pubsub.unsubscribe('a.b');

pubsub.publish('myTopic', 'some arguments')
    .then(onSuccess)
    .catch(onFailure);
 
pubsub.subscribe('myTopic', (event, ...args) => {
    event.resolve('success!');
});