Map<String, Object> getTrustingConfig(CertStores certStores, CertStores peerCertStores) {
            Map<String, Object> configs = certStores.getTrustingConfig(peerCertStores);
            configs.putAll(sslConfigOverrides);
            return configs;
        }
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