instance method call

# File actionpack/lib/action_controller/session/abstract_store.rb, line 175
      def call(env)
        prepare!(env)
        response = @app.call(env)

        session_data = env[ENV_SESSION_KEY]
        options = env[ENV_SESSION_OPTIONS_KEY]

        if !session_data.is_a?(AbstractStore::SessionHash) || session_data.loaded? || options[:expire_after]
          request = ActionController::Request.new(env)

          return response if (options[:secure] && !request.ssl?)
        
          session_data.send(:load!) if session_data.is_a?(AbstractStore::SessionHash) && !session_data.loaded?

          sid = options[:id] || generate_sid

          unless set_session(env, sid, session_data.to_hash)
            return response
          end

          request_cookies = env["rack.request.cookie_hash"]

          if (request_cookies.nil? || request_cookies[@key] != sid) || options[:expire_after]
            cookie = {:value => sid}
            cookie[:expires] = Time.now + options[:expire_after] if options[:expire_after]
            Rack::Utils.set_cookie_header!(response[1], @key, cookie.merge(options))
          end
        end

        response
      end