static void validate(SslEngineFactory oldEngineBuilder,
                             SslEngineFactory newEngineBuilder) throws SSLException {
            validate(createSslEngineForValidation(oldEngineBuilder, ConnectionMode.SERVER),
                    createSslEngineForValidation(newEngineBuilder, ConnectionMode.CLIENT));
            validate(createSslEngineForValidation(newEngineBuilder, ConnectionMode.SERVER),
                    createSslEngineForValidation(oldEngineBuilder, ConnectionMode.CLIENT));
        }
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