When I access any URL (browser or curl) using the Rack::Session::Cookie it raises the exception: ``` NoMethodError at / undefined method `rpartition' for nil:NilClass session_data, _, digest = cookie_data.rpartition('--') ``` file: rack-session-0.2.1/lib/rack/session/cookie.rb: in block in unpacked_cookie_data, line 229 Can be reproduced using the rack "hello, world" app: ``` require 'rack' require 'rack/session' use Rack::Session::Cookie, domain: '127.0.0.1:9292', expire_after: 3600*24, secret: '***********************unique secret key************************' run ->(env) { [ 200, { "Content-Type" => "text/html" }, [ "Hello World!" ]] } ```