code: function(start, end) {
        var current = parseInt(start), end = parseInt(end), values = [current]
        if (end > current) while (++current <= end) values.push(current)
        else               while (--current >= end) values.push(current)
        return '[' + values + ']'
      }
docs: Create a range string which can be evaluated to a native array.
  
  @param  {int} start
  @param  {int} end
  @return {string}
  @api public