void close() {
            sslEngine.closeOutbound();
            try {
                sslEngine.closeInbound();
            } catch (Exception e) {
                // ignore
            }
        }
Validator used to verify dynamic update of keystore used in inter-broker communication.
The validator checks that a successful handshake can be performed using the keystore and
truststore configured on this SslFactory.
clients/src/main/java/org/apache/kafka/common/security/ssl/SslFactory.java