如何在laravel中使用hasmanythrout

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class UserRole extends Model
{
    protected $table = 'user_role';

    public function user()
    {
        return $this->belongsTo(User::class);
    }

    public function role()
    {
        return $this->belongsTo(Role::class);
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public function permissions()
    {
        return $this->hasManyThrough(Permission::class, UserRole::class, 'user_id', 'role_id');
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Role extends Model
{
    public function permissions()
    {
        return $this->hasManyThrough(Permission::class, UserRole::class, 'role_id', 'user_id');
    }
}

$user = User::find(1);
$permissions = $user->permissions;