code: @JsMethod(name = "getConstructorJsDoc", namespace = "jscomp")
    public static String getConstructorJsDoc(String jsDoc) {
      if (Strings.isNullOrEmpty(jsDoc)) {
        return null;
      }
      Config config =
          Config.builder()
              .setLanguageMode(LanguageMode.ECMASCRIPT3)
              .setStrictMode(Config.StrictMode.SLOPPY)
              .setJsDocParsingMode(JsDocParsing.INCLUDE_DESCRIPTIONS_WITH_WHITESPACE)
              .build();
      JsDocInfoParser parser =
          new JsDocInfoParser(
              // Stream expects us to remove the leading /**
              new JsDocTokenStream(jsDoc.substring(3)),
              jsDoc,
              0,
              null,
              config,
              ErrorReporter.NULL_INSTANCE);
      parser.parse();
      JSDocInfo parsed = parser.retrieveAndResetParsedJSDocInfo();
      JSDocInfo params = parsed.cloneConstructorDoc();
      if (parsed.getParameterNames().isEmpty() && parsed.getSuppressions().isEmpty()) {
        return null;
      }
      JSDocInfoPrinter printer =
          new JSDocInfoPrinter(/* useOriginalName= */ true, /* printDesc= */ true);
      return printer.print(params).trim();
    }
docs: Gets JS Doc that should be moved to a constructor. Used to upgrade ES5 to ES6 classes and
  separate class from constructor comments.