java.lang.UnsupportedOperationException at io.netty.channel.socket.nio.NioServerSocketChannel.doConnect(NioServerSocketChannel.java:178)

I'm working on Netty tutorials in youtube.

I've below server code -

package yt.ingrim.p01;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.*;
import io.netty.channel.epoll.Epoll;
import io.netty.channel.epoll.EpollEventLoopGroup;
import io.netty.channel.epoll.EpollServerSocketChannel;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

public class Server {
    public static class MySimpleChannelInboundHandler extends SimpleChannelInboundHandler<Object> {
        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            super.channelActive(ctx);
            System.out.println("channel Connected --> " + ctx.channel());
        }

        @Override
        protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {

        }
    }
    public static final boolean EPOLL = Epoll.isAvailable();
    Class channelClazz = EPOLL? EpollServerSocketChannel.class : NioServerSocketChannel.class;

    public Server() throws Exception {
        EventLoopGroup eventLoopGroup = EPOLL? new EpollEventLoopGroup(): new NioEventLoopGroup();
        try {
            new ServerBootstrap()
                    .group(eventLoopGroup)
                    .channel(channelClazz)
                    .childHandler(new ChannelInitializer<Channel>() {
                        @Override
                        protected void initChannel(Channel ch) throws Exception {
                            ChannelPipeline cpl = ch.pipeline();
                            cpl.addLast("default_channel_handler", new MySimpleChannelInboundHandler());
                        }
                    }).bind(8000).sync().channel().closeFuture().syncUninterruptibly();
        } finally {
            eventLoopGroup.shutdownGracefully().await();
        }
    }
    public static void main(String[] args) throws Exception {
        new Server();
    }
}

The Client Code is -

package yt.ingrim.p01;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.epoll.Epoll;
import io.netty.channel.epoll.EpollEventLoopGroup;
import io.netty.channel.epoll.EpollServerSocketChannel;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

import java.net.InetSocketAddress;

public class Client {

    public static final boolean EPOLL = Epoll.isAvailable();

    Class channelClazz = EPOLL? EpollServerSocketChannel.class : NioServerSocketChannel.class;

    public Client() throws Exception {
        EventLoopGroup eventLoopGroup = EPOLL? new EpollEventLoopGroup(): new NioEventLoopGroup();
        try {
            new Bootstrap()
                    .group(eventLoopGroup)
                    .channel(channelClazz)
                    .remoteAddress(new InetSocketAddress("127.0.0.1", 8000))
                    .handler(new ChannelInitializer<Channel>() {
                        @Override
                        protected void initChannel(Channel ch) throws Exception {

                        }
                    }).connect().sync().channel().closeFuture().syncUninterruptibly();
        } finally {
            eventLoopGroup.shutdownGracefully().sync();
        }
    }
    public static void main(String []args) throws Exception {
        System.out.println(EPOLL);
        new Client();
    }
}

In my system EPOLL is false. When I run the server it is working fine.

When I run the client, I get the below error -

Exception in thread "main" java.lang.UnsupportedOperationException at io.netty.channel.socket.nio.NioServerSocketChannel.doConnect(NioServerSocketChannel.java:178) at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.connect(AbstractNioChannel.java:248) at io.netty.channel.DefaultChannelPipeline$HeadContext.connect(DefaultChannelPipeline.java:1342) at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:548) at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:533) at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:517) at io.netty.channel.DefaultChannelPipeline.connect(DefaultChannelPipeline.java:978) at io.netty.channel.AbstractChannel.connect(AbstractChannel.java:265) at io.netty.bootstrap.Bootstrap$3.run(Bootstrap.java:250) at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:174) at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:167) at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470) at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:569) at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) at java.base/java.lang.Thread.run(Thread.java:829)

My code is exactly same in the tutorial. What is the issue in my code. How can I fix this issue?

Netty version is - 4.1.82.Final Java Version is - 17

java --version
openjdk 17.0.3-oracle

My code is on github here