/**
  * Get the pivot attribute from a model.
  *
  * @param  \Illuminate\Database\Eloquent\Model  $model
  * @param  \Illuminate\Database\Eloquent\Relations\Relation  $parentRelation
  */
 public static function loadPivotAttribute(Model $model, Relation $parentRelation = null)
 {
     $attributes = $model->getAttributes();
     foreach ($attributes as $key => $value) {
         if ($key === 'pivot') {
             unset($model[$key]);
             $pivot = $parentRelation->newExistingPivot($value);
             $model->setRelation($key, $pivot);
         }
     }
 }