test

        size_t rd = sizeof(AuthHeader), end = backend.end();

        while (rd < end) {

        while (rd + sizeof(AuthData::Record) <= end) {

            std::shared_ptr<AuthData::Record> cur = std::make_shared<AuthData::Record>();

            cur->type = EmptyData;

            backend.setPos(rd);

            backend.read(reinterpret_cast<unsigned char*>(cur.get()), sizeof(AuthData::Record));

            rd = backend.getPos() + cur->datasize;

            size_t next = backend.getPos() + cur->datasize;

            if(next < backend.getPos() || next > end) break;

            rd = next;

            // Skip empty/deleted records

            if (cur->type == EmptyData)