code: def _handle_license_list(self, lics_set, cls=None):
          
          licenses = []
          for _, _, lics_member in self.graph.triples(
              (lics_set, self.spdx_namespace['member'], None)):
              try:
                  if (lics_member, RDF.type, self.spdx_namespace['ExtractedLicensingInfo']) in self.graph:
                      lics = self.handle_extracted_license(lics_member)
                      if lics is not None:
                          licenses.append(lics)
                  else:
                      licenses.append(self.handle_lics(lics_member))
              except CardinalityError:
                  self.value_error('LICS_LIST_MEMBER', lics_member)
                  break
          if len(licenses) > 1:
              return reduce(lambda a, b: cls(a, b), licenses)
          else:
              self.value_error('PKG_CONC_LIST', '')
              return
docs: Return a license representing a `cls` object (LicenseConjunction
          or LicenseDisjunction) from a list of license resources or None.