public Map<String, Integer> getExtensionFrequency(){
		Map<String, Integer> map = new HashMap<String, Integer>();
		
		for(Record record : log.getRecords()){
			String extension = record.getRequest().getUrl().getExtension().getExtension();
			Integer number = map.get(extension);
			if(number != null){
				map.remove(extension);
				map.put(extension, ++number);
			} else {
				map.put(extension, 1);
			}
		}
		
		return map;
	}