text: // See: http://youmightnotneedjquery.com/#ready
  function ready(fn) {
    if (document.readyState != "loading") {
      fn();
    } else if (document.addEventListener) {
      document.addEventListener("DOMContentLoaded", fn);
    } else {
      document.attachEvent("onreadystatechange", function () {
        if (document.readyState != "loading") fn();
      });
    }
  }
  
  // See: http://youmightnotneedjquery.com/#add_class
  function addClass(element, className) {
    if (element.classList) element.classList.add(className);
    else element.className += " " + className;
  }
  
  ready(() => {
    var hightClassName = "highlight"; // See 01.css
    var poemStanzas = document.querySelectorAll(".poem-stanza"); // Lookup all nodes with class poem-stanza
    for (var i = 0; i < poemStanzas.length; ++i) {
      var poemStanza = poemStanzas[i];
      addClass(poemStanza, hightClassName);
    }
  });
  