code: function (header, prevToken) {
          var options = this.options;
  
          if (header.depth > options.maxDepth) return;
  
          var headerText = utils.getHeader(header.text, prevToken);
  
          if (!headerText) return;
  
          var anchor = this._getAnchor(header.text, prevToken),
              indent = utils.getIndent(this._usedHeaders, header.depth);
  
          this._usedHeaders.unshift({
              depth: header.depth,
              indent: indent
          });
  
          this.data += indent + options.bullet + ' [' + headerText.replace(/\\/g, '\\\\') + '](#' + anchor + ')' + EOL;
      }
docs: Adds a TOC elemet
  @param {Object} [header]
  @param {Number} [header.depth]
  @param {String} [header.text]
  @returns {undefined}
  @public