class Registry::Download

def download
  require 'open-uri'
  File.open(File.join(Dir.tmpdir, self.filename), 'w') {|f| f.write open(self.url).read }
end

def filename
  File.basename(self.url)
end

def initialize(extension)
  super(extension.download_url, extension.name)
end

def install
  download
  unpack
  super
end

def unpack
  raise "Not Implemented!"
end