code: function (tag) {
                  var
                      len = this._openedTags.length;
                  if (len && this._openedTags[len - 1] === tag) {
                      this._openedTags.pop();
                      this._output("</" + tag + ">");
                  } else {
                      this._openTag(tag);
                  }
              }
docs: Open/Close tag depending if it has been opened previously (if it
  appears as the top tag on the stacked items)
  
  @param {String} tag
  @private