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kotlinlang

but I can share the like 4 relevant lines : 
In an InboundHandler : 
```
ctx.channel().attr(KEEP_ALIVE_KEY).set(HttpHeaders.isKeepAlive(req));
```
In your OutboundHandler :
```
    if (ctx.channel().attr(KEEP_ALIVE_KEY).get()) {
            HttpHeaders.setKeepAlive(res, true);

            ctx.writeAndFlush(response);
        } else {
            ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
        }
```