class Rack::ForwardRequest

def initialize(url, env = {})
  @url = URI(url)
  @env = env
  @env[PATH_INFO]       = @url.path
  @env[QUERY_STRING]    = @url.query  if @url.query
  @env[HTTP_HOST]       = @url.host   if @url.host
  @env[HTTP_PORT]       = @url.port   if @url.port
  @env[RACK_URL_SCHEME] = @url.scheme if @url.scheme
  super "forwarding to #{url}"
end