public List<Task> getUnompleteTask() {
        List<Task> uncompletedTasks = new ArrayList<Task>() ;
        for(Entry<String,Task> entry : taskMap.entrySet()) {
            Task task = entry.getValue() ;
            if(!task.getStatus().equals(Task.STATUS_DONE)) {
                uncompletedTasks.add(task) ;
            }
        }
        return uncompletedTasks ;
    }