nio-connect-proxy fails to send error response about swift-nio-examples HOT 2 CLOSED

    private func httpErrorAndClose(context: ChannelHandlerContext) {
        self.upgradeState = .upgradeFailed

        let headers = HTTPHeaders([("Content-Length", "0"), ("Connection", "close")])
        let head = HTTPResponseHead(version: .init(major: 1, minor: 1), status: .badRequest, headers: headers)
        context.write(self.wrapOutboundOut(.head(head)), promise: nil)
        context.write(self.wrapOutboundOut(.end(nil))).whenComplete { (_: Result<Void, Error>) in
            context.close(mode: .output, promise: nil)
        }
    }