def ranges(name=nil, tags=Selectable::Tags.new)
      return @ranges if name.nil?
      @ranges.select do |range| 
        ret = name.to_s == range.name.to_s &&
        (tags.nil? || range.tags >= tags)
        ret
      end
    end
def ranges(name=nil, tags=Selectable::Tags.new)
      return @ranges if name.nil?
      @ranges.select do |range| 
        ret = name.to_s == range.name.to_s &&
        (tags.nil? || range.tags >= tags)
        ret
      end
    end
obj.ranges(:do_request) =>
         [[:do_request_a, :do_request_z], [:do_request_a, ...]]