getDefaultParams(config) {
    return config
      ? {
        [pageParams.appId]: config.appId,
        [pageParams.appName]: config.appName,
        [pageParams.publicServerUrl]: config.publicServerURL,
      }
      : {};
  }
Extracts and returns the page default parameters from the Parse Server
configuration. These parameters are made accessible in every page served
by this router.
@param {Object} config The Parse Server configuration.
@returns {Object} The default parameters.