introduction 字段无法被更新

introduction字段使用update方法更新失败，查看手册后发现批量操作必须定义$fillable属性，$fillable属性定义了哪些字段可以被批量更新，经过测试去除name字段后用户名也更新失败，$fillable属性里面应该加上introduction字段

<?php

namespace App\Models;

use Illuminate\Contracts\Auth\MustVerifyEmail as MustVerifyEmailContract;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
use Illuminate\Auth\MustVerifyEmail as MustVerifyEmailTrait;

class User extends Authenticatable implements MustVerifyEmailContract
{
    use Notifiable, MustVerifyEmailTrait;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password', 'introduction',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];

    /**
     * The attributes that should be cast to native types.
     *
     * @var array
     */
    protected $casts = [
        'email_verified_at' => 'datetime',
    ];
}