@Override
        public String toString() {
            return "tlsProtocol=" + tlsProtocol +
                    ", useInlinePem=" + useInlinePem;
        }
Tests for the SSL transport layer. These use a test harness that runs a simple socket server that echos back responses.
clients/src/test/java/org/apache/kafka/common/network/SslTransportLayerTest.java