baoshi-was/app/Sign.php

<?php

namespace App;

use App\Traits\ModelTimeFormat;
use Illuminate\Database\Eloquent\Model;

use App\Traits\ModelLogChanging;

class Sign extends Model
{
    use ModelLogChanging;

    use ModelTimeFormat;
    const UPDATED_AT = null;
    protected $fillable=[
        'signable_type','signable_id','field','mark'
    ];
}