无法在Angular 6服务中找到'map‘

npm install rxjs

import { map } from 'rxjs/operators';

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';

@Injectable()
export class MyService {
  constructor(private http: HttpClient) {}

  getData(): Observable<any> {
    return this.http.get('api/data').pipe(
      map(response => {
        // 在这里对响应数据进行处理
        return response;
      })
    );
  }
}