/**
  * Handle the event.
  */
 public function handle(Request $request)
 {
     /* @var FieldType $field */
     foreach ($request->old() as $key => $value) {
         if ($field = $this->builder->getFormField($key)) {
             $field->setValue($value);
         }
     }
 }
 /**
  * Handle the validation.
  *
  * @param FormBuilder             $builder
  * @param DiskRepositoryInterface $disks
  * @param                         $attribute
  * @return bool
  */
 public function handle(FormBuilder $builder, DiskRepositoryInterface $disks, $attribute)
 {
     $fieldType = $builder->getFormField($attribute);
     $disk = array_get($fieldType->getConfig(), 'disk');
     if (is_numeric($disk) && !$disks->find($disk)) {
         return false;
     }
     if (!is_numeric($disk) && !$disks->findBySlug($disk)) {
         return false;
     }
     return true;
 }