class Log4JConfigurationMXBeanSingleton implements Log4JConfigurationMXBean {

    @Override
    public final void pollConfigurationFile(String file, long updateFrequencyMS) {
        if (file == null) {
            throw new IllegalArgumentException("file may not be null");
        }
        if (updateFrequencyMS <= 0) {
            throw new IllegalArgumentException("updateFrequencyMS must be positive (tried to pass in "
                    + updateFrequencyMS + ')');
        }

        synchronized (MONITOR) {
            if (this.updateFrequency != null) {
                throw new IllegalStateException("Can't set config file or polling frequency after polling has started");
            }
            this.configFile = file;
            this.updateFrequency = updateFrequencyMS;
        }

        configureAndWatch(file, updateFrequencyMS);
    }

      Log4JConfigurationMXBeanSingleton();

}