Tengo errores con el catchError de authService.ts es angular 7 <code>import { Injectable } from '@angular/core'; import urljoin from 'url...

Tengo errores con el catchError de authService.ts

es angular 7

import { Injectable } from '@angular/core';
import urljoin from 'url-join'
import { environment } from 'src/environments/environment';
import { User } from './user.model';
import { HttpHeaders, HttpClient, HttpErrorResponse } from '@angular/common/http';
import { map, catchError, first } from 'rxjs/operators';
import { Observable } from 'rxjs';
import { Router } from '@angular/router';
import { MatSnackBar } from '@angular/material';


@Injectable({
  providedIn: 'root'
})
export class AuthService {
  usersUrl: string;
  currentUser?: User;
  constructor(private http: HttpClient, private router: Router, private snackBar:MatSnackBar) {
     this.usersUrl =  urljoin(environment.apiUrl, 'auth');
     if(this.isLoggedIn()){
        const {userId,firstName, lastName, email} = JSON.parse(localStorage.getItem('user'));
        this.currentUser = new User(email,null, firstName, lastName,email);
     }
   }
  signup(user: User){
    const body = JSON.stringify(user);
    const headers =  new HttpHeaders({'Content-Type': 'application/json'});
    return this.http.post(urljoin(this.usersUrl,'signup'),body,{headers})
               .pipe( map((response: Response) => {
                    const json:any = response;
                    this.login(json);
                    return json;
                 }), catchError((error) => {
                   console.log(error);
                   Observable.throw(error);
                 }));
  }
  signin(user:User){
    const body = JSON.stringify(user);
    const headers =  new HttpHeaders({'Content-Type': 'application/json'});
    return this.http.post(urljoin(this.usersUrl,'signin'),body,{headers})
            .pipe( map((respon: Response)=>{
              const json:any = respon;
              this.login(json)
              return json;
            }), catchError((error: HttpErrorResponse) => {
              console.log(error);
              Observable.throw(error);
            }));
  }
  login = ({token, userId, firstName, lastName, email}) =>{
    this.currentUser =  new User(email,null, firstName,lastName,userId);
    localStorage.setItem('token',token);
    localStorage.setItem('user', JSON.stringify({userId,firstName,lastName,email}));
    this.router.navigateByUrl('/')
  }
  isLoggedIn(){
    return localStorage.getItem('token') !== null;
  }
  logout(){
    localStorage.clear();
    this.currentUser = null;
    this.router.navigateByUrl('/')
  }
  showError(message){
      this.snackBar.open(message, 'Close', { duration: 3000 });
  }
  public handleError = (error:any) => {
    const { error: { name }, message } = error;
    if(name==='TokenExpiredError'){
      this.showError('Tu sesión ha expirado')
    }else if(name==='JsonWebTokenError'){
      this.showError('Ocurrio un problema con tu sesión');
    }else{
      this.showError(message || 'HO HO! A ocurrido un error, vuelve a intentarlo');
    }
    this.logout();
  }
}

alguien tuvo el mismo problema ?