def parse
      case File.extname list
      when '.xml' || '.opml'
        Nokogiri::XML(load_list).xpath('//@xmlUrl').map(&:value)
      when '.json'
        JSON.parse(load_list)
      when '.txt'
        load_list.split("\n")
      end
    end
def parse
      case File.extname list
      when '.xml' || '.opml'
        Nokogiri::XML(load_list).xpath('//@xmlUrl').map(&:value)
      when '.json'
        JSON.parse(load_list)
      when '.txt'
        load_list.split("\n")
      end
    end
Parses OPML, JSON, or plain text documents and returns an Array of feed urls.

 @return [Array]