code: def handle_extracted_license(self, extr_lic):
          
          lic = self.parse_only_extr_license(extr_lic)
          if lic is not None:
              self.doc.add_extr_lic(lic)
          return lic
docs: Build and return an ExtractedLicense or None.
          Note that this function adds the license to the document.