protected SslTransportLayer buildTransportLayer(SslFactory sslFactory, String id, SelectionKey key, ChannelMetadataRegistry metadataRegistry) throws IOException {
        SocketChannel socketChannel = (SocketChannel) key.channel();
        return SslTransportLayer.create(id, key, sslFactory.createSslEngine(socketChannel.socket()),
            metadataRegistry);
    }
Constructs an SSL channel builder. ListenerName is provided only
for server channel builder and will be null for client channel builder.
clients/src/main/java/org/apache/kafka/common/network/SslChannelBuilder.java