@VisibleForTesting
    String getFailureCause(Throwable throwable) {
        String message = throwable.getMessage();
        if (message == null) {
            return throwable.toString();
        }

        Matcher matcher = OPEN_SSL_PATTERN.matcher(message);
        return matcher.find() ? matcher.group(1) : message;
    }
Stores info about the client and server's SSL certificates in the context, after a successful handshake.
<p>
User: michaels@netflix.com Date: 3/29/16 Time: 10:48 AM
zuul-core/src/main/java/com/netflix/zuul/netty/server/ssl/SslHandshakeInfoHandler.java