code: function ParserBlock() {
    /**
     * ParserBlock#ruler -> Ruler
     *
     * [[Ruler]] instance. Keep configuration of block rules.
     **/
    this.ruler = new Ruler();
  
    for (var i = 0; i < _rules.length; i++) {
      this.ruler.push(_rules[i][0], _rules[i][1], { alt: (_rules[i][2] || []).slice() });
    }
  }
docs: new ParserBlock()