如何使用angular读取从API发送的报头？

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';

@Injectable({
  providedIn: 'root'
})
export class ApiService {
  constructor(private httpClient: HttpClient) { }

  getData() {
    const url = 'https://api.example.com/data';
    return this.httpClient.get(url, { observe: 'response' });
  }
}

import { Component } from '@angular/core';
import { ApiService } from './api.service';

@Component({
  selector: 'app-root',
  template: `
    <button (click)="getData()">Get Data</button>
    <div>{{ responseHeaders }}</div>
  `
})
export class AppComponent {
  responseHeaders: string;

  constructor(private apiService: ApiService) { }

  getData() {
    this.apiService.getData().subscribe((response) => {
      this.responseHeaders = response.headers.get('content-type');
    });
  }
}