Document.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Document extends Model
{
    /**
     * Get the owner of the relationship which could either be a broker or a company
     */
    public function documentable()
    {
        return $this->morphTo('documentable', 'documentable_type', 'documentable_id');
       // The first argument is the function name, we can also use the magic constant __FUNCTION__ like so
        // return $this->morphTo(__FUNCTION__, 'documentable_type', 'documentable_id');
      
    }
}