code: function startTagBeforeHtml(p, token) {
      if (token.tagName === $.HTML) {
          p._insertElement(token, NS.HTML);
          p.insertionMode = BEFORE_HEAD_MODE;
      }
  
      else
          tokenBeforeHtml(p, token);
  }
docs: 12.2.5.4.2 The "before html" insertion mode ------------------------------------------------------------------