/**
  * Register field's custom validators.
  *
  * @param Factory     $factory
  * @param FormBuilder $builder
  * @param FieldType   $fieldType
  */
 protected function registerValidators(Factory $factory, FormBuilder $builder, FieldType $fieldType)
 {
     foreach ($fieldType->getValidators() as $rule => $validator) {
         $handler = array_get($validator, 'handler');
         if (is_string($handler) && !str_contains($handler, '@')) {
             $handler .= '@handle';
         }
         $factory->extend($rule, function ($attribute, $value, $parameters, Validator $validator) use($handler, $builder) {
             return $this->container->call($handler, compact('attribute', 'value', 'parameters', 'builder', 'validator'));
         }, array_get($validator, 'message'));
     }
 }