code: protected void saveProps(Properties props) throws IOException {
  
  		if (loadFromPropertiesFile) {
  			// Persist the change to the properties file.
  			File file = getPropsFile();
  			if (file != null) {
  				FileWriter writer = new FileWriter(file);
  				try {
  					props.store(writer, null);
  				} finally {
  					writer.close();
  				}
  			}
  		}
  	}
docs: Saves the specified Options properties to the properties file for the
  aggregator.
  
  @param props
  The properties to save
  @throws IOException