NativeEventEmitter

let emitter = NativeEventEmitter.make(myNativeModule)

let sub = emitter->NativeEventEmitter.addListener("onSomething", payload => {
  Console.log(payload)
})

emitter->NativeEventEmitter.listenerCount("onSomething") // int
emitter->NativeEventEmitter.removeAllListeners("onSomething")
sub->EventSubscription.remove