angular Location.onUrlChange如何正确取消订阅

import { Component, OnDestroy } from '@angular/core';
import { Location } from '@angular/common';
import { Subscription } from 'rxjs';

@Component({
  selector: 'app-example',
  template: '<p>Example component</p>',
})
export class ExampleComponent implements OnDestroy {
  private urlChangeSubscription: Subscription;

  constructor(private location: Location) {
    this.urlChangeSubscription = this.location.onUrlChange((url: string) => {
      // 处理URL更改事件的回调函数
    });
  }

  ngOnDestroy() {
    if (this.urlChangeSubscription) {
      this.urlChangeSubscription.unsubscribe();
    }
  }
}