def _record(self, entries):
        '''
        Return a string representing the Rock Ridge entry.
        Parameters:
         entries - The dr_entries or ce_entries to generate a record for.
        Returns:
         A string representing the Rock Ridge entry.
        '''
        outlist = []
        if entries.sp_record is not None:
            outlist.append(entries.sp_record.record())
        if entries.rr_record is not None:
            outlist.append(entries.rr_record.record())
        for nm_record in entries.nm_records:
            outlist.append(nm_record.record())
        if entries.px_record is not None:
            outlist.append(entries.px_record.record(self.rr_version))
        for sl_record in entries.sl_records:
            outlist.append(sl_record.record())
        if entries.tf_record is not None:
            outlist.append(entries.tf_record.record())
        if entries.cl_record is not None:
            outlist.append(entries.cl_record.record())
        if entries.pl_record is not None:
            outlist.append(entries.pl_record.record())
        if entries.re_record is not None:
            outlist.append(entries.re_record.record())
        for es_record in entries.es_records:
            outlist.append(es_record.record())
        if entries.er_record is not None:
            outlist.append(entries.er_record.record())
        if entries.ce_record is not None:
            outlist.append(entries.ce_record.record())
        for pd_record in entries.pd_records:
            outlist.append(pd_record.record())
        if entries.st_record is not None:
            outlist.append(entries.st_record.record())
        if entries.sf_record is not None:
            outlist.append(entries.sf_record.record())
        return b''.join(outlist)