code: public static UserAgent newUserAgent(Settings settings)
      {
          UserAgent.Factory factory = Factories.newInstance(settings, Keys.UA_FACTORY_KEY);
          return factory.newUserAgent(settings);
      }
docs: Creates a new UserAgent with the given configuration; the UserAgent must be started.
  
  @param settings the configuration for the UserAgent
  @return a new UserAgent with the given configuration