docs: def run(self):
          has_npm = npm_installation_check()
          if has_npm:
              run_npm_install()
          else:
              print("Warning: npm not installed using prebuilded js files!",
                    file=sys.stderr)
          """
          Download npm packages required by package.json and extract required
          files from them
          """
          for js in JS_FILES:
              downloaded_js_name = os.path.join(TOP_DIR, js)
              installed_js_name = os.path.join(TOP_DIR, "sphinx_hwt", "html", js)
              if has_npm:
                  assert os.path.exists(downloaded_js_name), downloaded_js_name
                  os.makedirs(os.path.dirname(installed_js_name), exist_ok=True)
                  copyfile(downloaded_js_name, installed_js_name)
                  print("copy generated from NPM packages", installed_js_name)
              else:
                  if os.path.exists(installed_js_name):
                      print("using prebuilded", installed_js_name)
                  else:
                      raise Exception("Can not find npm,"
                                      " which is required for the installation "
                                      "and this is pacpage has not js prebuilded")