protected function checkUndefined(&$value, $schema = null, JsonPointer $path = null, $i = null, $fromDefault = false)
    {
        $validator = $this->factory->createInstanceFor('undefined');

        $validator->check($value, $this->factory->getSchemaStorage()->resolveRefSchema($schema), $path, $i, $fromDefault);

        $this->addErrors($validator->getErrors());
    }