private NioEchoServer createEchoServer(Args args, ListenerName listenerName, SecurityProtocol securityProtocol) throws Exception {
        return NetworkTestUtils.createEchoServer(listenerName, securityProtocol, new TestSecurityConfig(args.sslServerConfigs), null, TIME);
    }
Tests invalid ssl.engine.factory plugin class
clients/src/test/java/org/apache/kafka/common/network/SslTransportLayerTest.java