text: "use strict";
  
  function changeAttribute(){
    var el = document.getElementById("mySelect");
    el.setAttribute("options", [1, 2, 3]);
  }
  
  function addOption(){
    var el = document.querySelector("#mySelect");
    var li = document.createElement("li");
    li.textContent = 123;
    li.slot = "items";
    el.appendChild(li);
  }
  