docs: function () {
              if (!el) {
                  return;
              }
  
              if (el.nodeType === NODE_TYPE.TEXT_NODE) {
                  while (el.nextSibling && el.nextSibling.nodeType === NODE_TYPE.TEXT_NODE) {
                      el.nodeValue += el.nextSibling.nodeValue;
                      el.parentNode.removeChild(el.nextSibling);
                  }
              } else {
                  dom(el.firstChild).normalizeTextNodes();
              }
              dom(el.nextSibling).normalizeTextNodes();
          }