code: public void fireUpdateEvent(final long timestamp){
  		synchronized(listeners){
  			for (final ConfigurationSourceListener listener : listeners){
  				try{
  					log.debug("Calling configurationSourceUpdated on "+listener);
  					listener.configurationSourceUpdated(this);
  				}catch(final Exception e){
  					log.error("Error in notifying configuration source listener:"+listener, e);
  				}
  			}
  		}
  		lastChangeTimestamp = timestamp;
  	}
docs: Called by the ConfigurationSourceRegistry if a change in the underlying source is detected.
  
  @param timestamp a long.