docs: public ArrayList<String> tag2List(String src) {
  		if(src==null||src.length()==0)
  			return null;
  		ArrayList<String> res =null;
  		try {
  			Instance inst = new Instance(src);
  			String[] preds = _tag(inst);
  			res  = FormatCWS.toList(inst, preds);
  		} catch (Exception e) {
  			e.printStackTrace();
  		}
  		return res;
  	}