Using Rails Atom builder with non-AR objects

atom_builder_example.rb

atom_feed do |feed|
  feed.title "Some title"
  feed.updated Time.now
  @feed_entries.each do |item|
    feed.entry item, {id:42, url:"http://this_object.com/url"} do |entry|
      #code for entry here
    end
  end
end