code: static
    public
    void configureAndWatch(String configFilename, long delay) {
      XMLWatchdog xdog = new XMLWatchdog(configFilename);
      xdog.setDelay(delay);
      xdog.start();
    }
docs: Read the configuration file <code>configFilename</code> if it
  exists. Moreover, a thread will be created that will periodically
  check if <code>configFilename</code> has been created or
  modified. The period is determined by the <code>delay</code>
  argument. If a change or file creation is detected, then
  <code>configFilename</code> is read to configure log4j.
  
  @param configFilename A log4j configuration file in XML format.
  @param delay The delay in milliseconds to wait between each check.