@Override
		public int compare(Object o1, Object o2) {
			// TODO Auto-generated method stub
			String arg0 = o1.toString();
			String arg1 = o2.toString();
			if (!base_map.containsKey(arg0) || !base_map.containsKey(arg1)) {
				return 0;
			}
			if (base_map.get(arg0) < base_map.get(arg1)) {
				return 1;
			} else if (base_map.get(arg0) == base_map.get(arg1)) {
				return 0;
			} else {
				return -1;
			}
		}