RxJS：Multicasting运算符publishLast

publishBehaviour使用AsyncSubject，并返回ConnectableObservable。connect()方法必须用于订阅创建的可观察对象。

例

import { interval } from 'rxjs';
import { take, publishLast} from 'rxjs/operators';

let observer = interval(1000).pipe(
   take(10),
   publishLast()
);
const subscribe_one = observer.subscribe(
   x => console.log("Value from Sub1 = "+x)
);
const subscribe_two = observer.subscribe(
   x => console.log("Value from Sub2 = "+x)
);
observer.connect();

输出