class ActionDispatch::DebugExceptions

def call(env)
  begin
    response = @app.call(env)
    if response[1]['X-Cascade'] == 'pass'
      body = response[2]
      body.close if body.respond_to?(:close)
      raise ActionController::RoutingError, "No route matches [#{env['REQUEST_METHOD']}] #{env['PATH_INFO'].inspect}"
    end
  rescue Exception => exception
    raise exception if env['action_dispatch.show_exceptions'] == false
  end
  exception ? render_exception(env, exception) : response
end