@Override
    public void close() {
        tlsEngine.close();
    }
A crypto engine that supports both tls encrypted connections and
unencrypted connections. The use of tls for incoming connections is
auto-detected using clever heuristics. The use of tls for outgoing
connections is controlled by the useTlsWhenClient flag given to the
constructor.
jrt/src/com/yahoo/jrt/MaybeTlsCryptoEngine.java