Method add

packages/core/src/defer/timer_scheduler.ts:66–70

(delay: number, callback: VoidFunction, ngZone: NgZone)

  deferred: Array<number | VoidFunction> = [];

  add(delay: number, callback: VoidFunction, ngZone: NgZone) {
    const target = this.executingCallbacks ? this.deferred : this.current;
    this.addToQueue(target, Date.now() + delay, callback);
    this.scheduleTimer(ngZone);
  }

  remove(callback: VoidFunction) {
    const {current, deferred} = this;