public static void main(String... args){
   var api = new WhatsappAPI();
   api.registerListener(new ChatListener(api));
   api.connect();
}

record ChatListener(WhatsappAPI api) implements WhatsappListener {
    public void onChatsReceived() {
        var chat = api.manager().findChatByName("chat").orElseThrow();
        loadChat(chat);
    }

   private void loadChat(WhatsappChat chat){
      var last = chat.messages().size();
      api.loadConversation(chat, chat.messages().get(0), 200).get(); // Will load 200 messages
      if(last != chat.messages().size()){
         loadChat(chat);
      }

      var file = new File(System.getProperty("user.home"), "chat.txt").toPath();
      chat.messages().forEach(message -> Files.writeString(file, message.text().orElse("Something else"), StandardOpenOptions.APPEND));
   }
}