Rx.Observable.prototype.subscribeOnCompleted(onCompleted, [thisArg])
Subscribes a function to invoke upon graceful termination of the observable sequence.
参数
onCompleted(Function): Function to invoke upon graceful termination of the observable sequence.[thisArg](Any): Object to use as this when executing callback.
返回值
(Disposable): The source sequence whose subscriptions and unsubscriptions happen on the specified scheduler.