code: def _populate_warcinfo(self, extra_fields=None):
          '''Add the metadata to the Warcinfo record.'''
          self._warcinfo_record.set_common_fields(
              WARCRecord.WARCINFO, WARCRecord.WARC_FIELDS)
  
          info_fields = NameValueRecord(wrap_width=1024)
          info_fields['Software'] = self._params.software_string \
              or self.DEFAULT_SOFTWARE_STRING
          info_fields['format'] = 'WARC File Format 1.0'
          info_fields['conformsTo'] = \
              'http://bibnum.bnf.fr/WARC/WARC_ISO_28500_version1_latestdraft.pdf'
  
          if extra_fields:
              for name, value in extra_fields:
                  info_fields.add(name, value)
  
          self._warcinfo_record.block_file = io.BytesIO(
              bytes(info_fields) + b'\r\n')
          self._warcinfo_record.compute_checksum(f _populate_warcinfo(self, extra_fields=None):
          '''Add the metadata to the Warcinfo record.'''
          self._warcinfo_record.set_common_fields(
              WARCRecord.WARCINFO, WARCRecord.WARC_FIELDS)
  
          info_fields = NameValueRecord(wrap_width=1024)
          info_fields['Software'] = self._params.software_string \
              or self.DEFAULT_SOFTWARE_STRING
          info_fields['format'] = 'WARC File Format 1.0'
          info_fields['conformsTo'] = \
              'http://bibnum.bnf.fr/WARC/WARC_ISO_28500_version1_latestdraft.pdf'
  
          if extra_fields:
              for name, value in extra_fields:
                  info_fields.add(name, value)
  
          self._warcinfo_record.block_file = io.BytesIO(
              bytes(info_fields) + b'\r\n')
          self._warcinfo_record.compute_checksum()
docs: Add the metadata to the Warcinfo record.