Erro no logout

import { Injectable } from '@angular/core'; import { BehaviorSubject } from 'rxjs'; import { TokenService } from '../token/token.service'; import { User } from './user'; import * as jtw_decode from 'jwt-decode';

@Injectable({ providedIn: 'root' }) export class UserService { logout() { throw new Error('Method not implemented.'); } static getUser(): import("rxjs").Observable { throw new Error('Method not implemented.'); }

private userSubject = new BehaviorSubject<User>(null);

constructor(private tokenService: TokenService) {
    this.tokenService.hasToken() &&
    this.decodeAndNotify
 }

setToken(token: string) {
    this.tokenService.setToken(token);
    this.decodeAndNotify();
}

getUser() {
 return this.userSubject.asObservable();
}


private decodeAndNotify(){
 const token = this.tokenService.getToken()   
 const user= jtw_decode(token) as User;
 this.userSubject.next(user);
}

    logout (){
     this.tokenService.removeToken();
     this.userSubject.next(null);
 }
}