public static @Nullable String getHelpUrl(@Nullable String id) {
    id = StringUtil.notNullize(id, "top");

    for (WebHelpProvider provider : WEB_HELP_PROVIDER_EP_NAME.getExtensions()) {
      if (id.startsWith(provider.getHelpTopicPrefix())) {
        String url = provider.getHelpPageUrl(id);
        if (url != null) {
          return url;
        }
      }
    }

    if (MacHelpUtil.isApplicable() && MacHelpUtil.invokeHelp(id)) {
      return null;
    }

    Function1<String, Url> urlSupplier = ExternalProductResourceUrls.getInstance().getHelpPageUrl();
    if (urlSupplier == null) return null;
    return IdeUrlTrackingParametersProvider.getInstance().augmentUrl(urlSupplier.invoke(id).toExternalForm());
  }
public static @Nullable String getHelpUrl(@Nullable String id)