code: protected static StopwatchSource<HttpServletRequest> initStopwatchSource(FilterConfig filterConfig, Manager manager) {
  		String stopwatchSourceClass = filterConfig.getInitParameter(SimonServletFilter.INIT_PARAM_STOPWATCH_SOURCE_CLASS);
  		StopwatchSource<HttpServletRequest> stopwatchSource = createMonitorSource(stopwatchSourceClass, manager);
  
  		injectSimonPrefixIntoMonitorSource(filterConfig, stopwatchSource);
  
  		String cache = filterConfig.getInitParameter(SimonServletFilter.INIT_PARAM_STOPWATCH_SOURCE_CACHE);
  		stopwatchSource = wrapMonitorSourceWithCacheIfNeeded(stopwatchSource, cache);
  
  		return stopwatchSource;
  	}
docs: Create and initialize the stopwatch source depending on the filter init parameters. Both
  monitor source class ({@link SimonServletFilter#INIT_PARAM_STOPWATCH_SOURCE_CLASS} and whether
  to cache results ({@link SimonServletFilter#INIT_PARAM_STOPWATCH_SOURCE_CACHE}) can be adjusted.
  
  @param filterConfig Filter configuration
  @return Stopwatch source