Laravel6 在使用 jwt 认证，最后生成 token 的时候报错

<?php

namespace App\Http\Controllers;

use Illuminate\Support\Facades\Auth;
use App\Http\Controllers\Controller;
use Tymon\JWTAuth\Facades\JWTAuth;
use Illuminate\Support\Facades\Validator;
class AuthController extends Controller
{
    /**
     * Create a new AuthController instance.
     *
     * @return void
     */
    public function __construct()
    {
       $this->middleware('auth:api', ['except' => ['login']]);
    }

    /**
     * Get a JWT via given credentials.
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function login()
    {
        $credentials = request(['email', 'password']);

        if (! $token = auth('api')->attempt($credentials)) {
            return response()->json(['error' => 'Unauthorized'], 401);
        }
        // 在这里的时候报错了，Method Illuminate\Auth\SessionGuard::factory does not exist.
        return $this->respondWithToken( $token );
    }

    /**
     * Get the authenticated User.
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function me()
    {
        return response()->json(auth()->user());
    }

    /**
     * Log the user out (Invalidate the token).
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function logout()
    {
        auth()->logout();

        return response()->json(['message' => 'Successfully logged out']);
    }

    /**
     * Refresh a token.
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function refresh()
    {
        return $this->respondWithToken(auth()->refresh());
    }

    /**
     * Get the token array structure.
     *
     * @param  string $token
     *
     * @return \Illuminate\Http\JsonResponse
     */
    protected function respondWithToken($token)
    {
        return response()->json([
            'access_token' => $token,
            'token_type' => 'bearer',
            'expires_in' => auth()->factory()->getTTL() * 60
        ]);
    }
}Copy