Laravel 5.2.29使用Auth::guard('；one'；）、Auth::guard('；

请帮助我解决这个问题

我想使用多重身份验证。

我的Laravel版本是5.2.*（5.2.29）

我做所有写在文件中的事情

//congig/auth.php
<?php
return [
'defaults' => [
    'guard' => 'web',
    'passwords' => 'users',
],
'guards' => [
    'web' => [
        'driver' => 'session',
        'provider' => 'users',
    ],
    'api' => [
        'driver' => 'token',
        'provider' => 'users',
    ],
    'admin' => [
        'driver' => 'token',
        'provider' => 'adminProvider',
    ],
],
'providers' => [
    'users' => [
        'driver' => 'eloquent',
        'model' => App'User::class,
    ],
    'adminProvider' => [
        'driver' => 'eloquent',
        'model' => App'User::class,
    ],
],
'passwords' => [
        'users' => [
            'provider' => 'users',
            'email' => 'auth.emails.password',
            'table' => 'password_resets',
            'expire' => 60,
        ],
    ],
];
 But 
 Auth::guard('api')->attempt(['email'=>som@email.com,...])

它给出以下错误

AuthController.php中的致命错误异常第34行：

调用未定义的方法Illuminate''Auth''TokenGuard:：attempt（）我做错了什么？