public static String findBasename(String filename) {
		String regex = "((_[a-z]{2}){0,2})((_[A-Z]{2}){0,1})(\\.properties)";
		
		Pattern pattern = Pattern.compile(regex);
		
		Matcher m = pattern.matcher(filename);
		if (m.find()) {
			String name = m.group(0);
			int idx = filename.indexOf(name);
			return filename.substring(0, idx);
		}
		
		return null;
	}