code: def get_extr_lic_name(self, extr_lic):
          
          extr_name_list = list(self.graph.triples((extr_lic, self.spdx_namespace['licenseName'], None)))
          if len(extr_name_list) > 1:
              self.more_than_one_error('extracted license name')
              return
          elif len(extr_name_list) == 0:
              return
          return self.to_special_value(extr_name_list[0][2])
docs: Return the license name from an ExtractedLicense or None