strprfcrm/app/Models/Contract.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Contract extends Model
{
    use HasFactory;
    const DEFAULT_SORT_BY = 'contract_date';
    protected $fillable = ['year', 'contract_number', 'contract_date'];
}