def fresh_when(options)
options.assert_valid_keys(:etag, :last_modified, :public)
response.etag = options[:etag] if options[:etag]
response.last_modified = options[:last_modified] if options[:last_modified]
if options[:public]
cache_control = response.headers["Cache-Control"].split(",").map {|k| k.strip }
cache_control.delete("private")
cache_control.delete("no-cache")
cache_control << "public"
response.headers["Cache-Control"] = cache_control.join(', ')
end
if request.fresh?(response)
head :not_modified
end
end