protected function getProperty($object, $key)
    {
        if (isset($object->{$key}) &&
            (
                (is_int($object->{$key}) && $object->{$key} != 0) ||
                (is_string($object->{$key}) && $object->{$key} != '')
            )
        ) {
            return $object->{$key};
        }

        return null;
    }