# File lib/FileCache.rb, line 84
  def make_file_system_image_list
    urls=[]
    Dir.glob("#{url_cache_dir}/*.cached.info").each do |info_file|
      url=File.open(info_file,"r").read.chomp
      urls<<url if (FileSystemImage.is_file_system_image_filename?(url))
    end
    File.open(@url_cache_list,"w") {|f| f<< urls.join("\n")}
  end