[Question]: Server端回包立刻关闭连接，OnTraffic 收不到最后一个包的数据 about gnet HOT 11 CLOSED

package jmtpclient

import (
	"bufio"
	"fmt"
	"github.com/panjf2000/gnet/v2"
	"net"
	"testing"
	"time"
)

func TestTcpClient(t *testing.T) {
	listen, err := net.Listen("tcp", "127.0.0.1:9999")
	if err != nil {
		fmt.Println("Listen() failed, err: ", err)
		return
	}
	go func() {
		for {
			conn, err := listen.Accept() // 监听客户端的连接请求
			if err != nil {
				fmt.Println("Accept() failed, err: ", err)
				continue
			}
			go process(conn) // 启动一个goroutine来处理客户端的连接请求
		}
	}()

	cli, err := gnet.NewClient(&GNetClient{}, gnet.WithMulticore(true))
	defer cli.Stop()
	if err != nil {
		t.Error(err)
	}
	cli.Start()
	_, err = cli.Dial("tcp", "127.0.0.1:9999")
	if err != nil {
		t.Error(err)
	}
	time.Sleep(10 * time.Second)
}

func process(conn net.Conn) {
	defer conn.Close() // 关闭连接
	for {
		reader := bufio.NewReader(conn)
		var buf [128]byte
		n, err := reader.Read(buf[:]) // 读取数据
		if err != nil {
			fmt.Println("read from client failed, err: ", err)
			break
		}
		recvStr := string(buf[:n])
		fmt.Println("收到Client端发来的数据：", recvStr)
		conn.Write([]byte(recvStr)) // 发送数据
		conn.Close()
	}
}

type GNetClient struct {
	gnet.BuiltinEventEngine
}

func (G GNetClient) OnBoot(eng gnet.Engine) (action gnet.Action) {
	return gnet.None
}

func (G GNetClient) OnOpen(c gnet.Conn) (out []byte, action gnet.Action) {
	return []byte("test"), gnet.None
}

func (G GNetClient) OnClose(c gnet.Conn, err error) (action gnet.Action) {
	return gnet.Close
}

func (G GNetClient) OnTraffic(c gnet.Conn) (action gnet.Action) {
	buf, err := c.Next(4)
	if err != nil {
		fmt.Println(err)
	} else {
		fmt.Println("======================" + string(buf))
	}
	return gnet.None
}