public ArrayList<Message> getAllMessages(String authorName) {
   ArrayList<Message> finalList = new ArrayList<Message>();
   ArrayList<Message> al = new ArrayList<Message>(messages.values());
   for (Message m : al) {
     if (m.getAuthor().equals(authorName)) finalList.add(m);
   }
   return finalList;
 }
 public Message editMessage(Message message) {
   messages.put(message.getId(), message);
   return message;
 }
 public Message addMessage(Message message) {
   message.setId(messages.size() + 1);
   // Message m = new Message(messages.size()+1, message.getMessage());
   messages.put(messages.size() + 1, message);
   return message;
 }