# Chapter 1
This is a test of the alarm system
{{#angular ./sample-2.ts#AnnounceComponent hide}}
more test stuff
{{#angular ./sample-2.ts#ConvinceComponent collapsed}}
even more test stuff
```ts,angular
import {Component, ChangeDetectionStrategy, signal} from '@angular/core';
@Component({
selector: 'my-test',
standalone: true,
template: `<p>{{counter()}} <button (click)="increase()">increase</button></p>`,
changeDetection: ChangeDetectionStrategy.OnPush,
})
export class TestComponent {
/** @keep lalalal */
counter = signal(0);
/**
* @keep
* lalalalalala
*/
increase() {
this.counter.set(this.counter() + 1);
}
}
```