public List<String> whatPerson(String nickName) throws NickNameNotExist{
		if(!nickNameAlreadyExist(nickName)) throw new NickNameNotExist();
		
		for (Personne p : listPer) {
			if(p.getListNickName().contains(nickName)) {
				LinkedList<String> list = new LinkedList<String>();
				list.add(p.getName());
				return app.application(list);
			}
		}
		return app.appError("Erreur");
	}