protected function isSynced(RecordInterface $inner, RecordInterface $outer): bool
    {
        if (empty($inner->primaryKey()) || empty($outer->primaryKey())) {
            //Parent not saved
            return false;
        }

        //Comparing FK values
        return $outer->getField(
                $this->key(Record::OUTER_KEY)
            ) == $inner->getField(
                $this->key(Record::INNER_KEY)
            );
    }