Как обернуть элементы в обертку ul в typescript?

Выкладываю код ниже:

document.body.onload = addMessage;
var my_autor_li: any = null;
var my_bot_li: any = null;
class User {
  question: string;
  answer: string;
  constructor(_question: string, _answer: string) {
    this.question = _question;
    this.answer = _answer;
  }
  setData(): string {
    if (localStorage.getItem(this.question) == null) {
      this.answer = prompt('Введите ответ сами', "")
      localStorage.setItem(this.question, this.answer);
    }
    return this.question;
  }
  getData(): string {
    return localStorage.getItem(this.question);
  }
  allMessages(): void {
  }
}


function addMessage() {
  var question: string = (<HTMLInputElement>document.getElementById("input-id-quest")).value;
  var answer: string;
  var dialogue: User = new User(question, answer);
  dialogue.setData();
  dialogue.getData();
  dialogue.allMessages();

  var author = document.createElement("li");
  var bot = document.createElement("li");
  author.innerHTML = '<p class="author">' + 'Пользователь: ' + dialogue.setData() + '</p>';
  bot.innerHTML = '<p class="bot">' + 'Бот ответил: ' + dialogue.getData() + '</p>';
  my_autor_li = document.getElementById("content");
  my_bot_li = document.getElementById("content");
  document.body.insertBefore(author, my_autor_li);
  document.body.insertBefore(bot, my_bot_li);
  (<HTMLInputElement>document.getElementById("input-id-quest")).value = "";
}