You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: update-www-meta.rb
    path of file: ./repos/jruby/test/tool/releng
    
    the code of the file until where you have to start completion: #!/usr/bin/env ruby
require "open-uri"
require "yaml"

class Tarball
  attr_reader :version, :size, :sha1, :sha256, :sha512

  def initi
    
  def self.update_downloads_yml(ver, xy, wwwdir)
    filename = "_data/downloads.yml"
    data = File.read(File.join(wwwdir, filename))

    if /^preview:\n\n(?:  .*\n)*  - #{Regexp.escape(xy)}\./ =~ data
      if ver.include?("-")
        data.sub!(/^  - #{Regexp.escape(xy)}\..*/, "  - #{ver}")
      else
        data.sub!(/^  - #{Regexp.escape(xy)}\..*\n/, "")
        data.sub!(/(?<=^stable:\n\n)/, "  - #{ver}\n")
      end