### Question:
ProtocolNegotiators { @VisibleForTesting static void logSslEngineDetails(Level level, ChannelHandlerContext ctx, String msg, @Nullable Throwable t) { if (!log.isLoggable(level)) { return; } SslHandler sslHandler = ctx.pipeline().get(SslHandler.class); SSLEngine engine = sslHandler.engine(); StringBuilder builder = new StringBuilder(msg); builder.append("\nSSLEngine Details: [\n"); if (engine instanceof OpenSslEngine) { builder.append(" OpenSSL, "); builder.append("Version: 0x").append(Integer.toHexString(OpenSsl.version())); builder.append(" (").append(OpenSsl.versionString()).append("), "); builder.append("ALPN supported: ").append(OpenSsl.isAlpnSupported()); } else if (JettyTlsUtil.isJettyAlpnConfigured()) { builder.append(" Jetty ALPN"); } else if (JettyTlsUtil.isJettyNpnConfigured()) { builder.append(" Jetty NPN"); } else if (JettyTlsUtil.isJava9AlpnAvailable()) { builder.append(" JDK9 ALPN"); } builder.append("\n TLS Protocol: "); builder.append(engine.getSession().getProtocol()); builder.append("\n Application Protocol: "); builder.append(sslHandler.applicationProtocol()); builder.append("\n Need Client Auth: " ); builder.append(engine.getNeedClientAuth()); builder.append("\n Want Client Auth: "); builder.append(engine.getWantClientAuth()); builder.append("\n Supported protocols="); builder.append(Arrays.toString(engine.getSupportedProtocols())); builder.append("\n Enabled protocols="); builder.append(Arrays.toString(engine.getEnabledProtocols())); builder.append("\n Supported ciphers="); builder.append(Arrays.toString(engine.getSupportedCipherSuites())); builder.append("\n Enabled ciphers="); builder.append(Arrays.toString(engine.getEnabledCipherSuites())); builder.append("\n]"); log.log(level, builder.toString(), t); } private  ProtocolNegotiators(); static ProtocolNegotiator serverPlaintext(); static ProtocolNegotiator serverTls(final SslContext sslContext); static ProtocolNegotiator httpProxy(final SocketAddress proxyAddress,
      final @Nullable String proxyUsername, final @Nullable String proxyPassword,
      final ProtocolNegotiator negotiator); static ProtocolNegotiator tls(SslContext sslContext); static ProtocolNegotiator plaintextUpgrade(); static ProtocolNegotiator plaintext();  }### Answer:
@Test public void engineLog() { ChannelHandler handler = new ServerTlsHandler(sslContext, grpcHandler); pipeline.addLast(handler); channelHandlerCtx = pipeline.context(handler); Logger logger = Logger.getLogger(ProtocolNegotiators.class.getName()); Filter oldFilter = logger.getFilter(); try { logger.setFilter(new Filter() { @Override public boolean isLoggable(LogRecord record) { return false; } }); ProtocolNegotiators.logSslEngineDetails( Level.INFO, channelHandlerCtx, "message", new Exception("bad")); } finally { logger.setFilter(oldFilter); } }