code: def upload(self, cmd: str, meta: dict):
          
          index = os.path.join(self.cached_repo, self.INDEX_FILE)
          if os.path.exists(index):
              os.remove(index)
          self._log.info("Writing the new index.json ...")
          with open(index, "w") as _out:
              json.dump(self.contents, _out)
          git.add(self.cached_repo, [index])
          message = self.COMMIT_MESSAGES[cmd].format(**meta)
          if self.signoff:
              global_conf_path = os.path.expanduser("~/.gitconfig")
              if os.path.exists(global_conf_path):
                  with open(global_conf_path, "br") as _in:
                      conf = ConfigFile.from_file(_in)
                      try:
                          name = conf.get(b"user", b"name").decode()
                          email = conf.get(b"user", b"email").decode()
                          message += self.DCO_MESSAGE.format(name=name, email=email)
                      except KeyError:
                          self._log.warning(
                              "Did not find name or email in %s, committing without DCO.",
                              global_conf_path)
              else:
                  self._log.warning("Global git configuration file %s does not exist, "
                                    "committing without DCO.", global_conf_path)
          else:
              self._log.info("Committing the index without DCO.")
          git.commit(self.cached_repo, message=message)
          self._log.info("Pushing the updated index ...")
          # TODO: change when https://github.com/dulwich/dulwich/issues/631 gets addressed
          git.push(self.cached_repo, self.remote_url, b"master")
          if self._are_local_and_remote_heads_different():
              self._log.error("Push has failed")
              raise ValueError("Push has failed")
docs: Push the current state of the registry to Git.