code: def convert_all(cls, records):
          
          out = ["<collection>"]
          for rec in records:
              conversion = cls(rec)
              out.append(conversion.convert())
          out.append("</collection>")
          return "\n".join(out)
docs: Convert the list of bibrecs into one MARCXML.
  
          >>> from harvestingkit.bibrecord import BibRecordPackage
          >>> from harvestingkit.inspire_cds_package import Inspire2CDS
          >>> bibrecs = BibRecordPackage("inspire.xml")
          >>> bibrecs.parse()
          >>> xml = Inspire2CDS.convert_all(bibrecs.get_records())
  
          :param records: list of BibRecord dicts
          :type records: list
  
          :returns: MARCXML as string