private SaslChannelBuilder createChannelBuilder(SecurityProtocol securityProtocol, String saslMechanism) {
        Class<?> loginModule;
        switch (saslMechanism) {
            case "PLAIN":
                loginModule = PlainLoginModule.class;
                break;
            case "SCRAM-SHA-256":
                loginModule = ScramLoginModule.class;
                break;
            case "OAUTHBEARER":
                loginModule = OAuthBearerLoginModule.class;
                break;
            case "GSSAPI":
                loginModule = TestGssapiLoginModule.class;
                break;
            default:
                throw new IllegalArgumentException("Unsupported SASL mechanism " + saslMechanism);
        }
        TestJaasConfig jaasConfig = new TestJaasConfig();
        jaasConfig.addEntry("jaasContext", loginModule.getName(), new HashMap<>());
        JaasContext jaasContext = new JaasContext("jaasContext", JaasContext.Type.SERVER, jaasConfig, null);
        Map<String, JaasContext> jaasContexts = Collections.singletonMap(saslMechanism, jaasContext);
        return new SaslChannelBuilder(ConnectionMode.CLIENT, jaasContexts, securityProtocol, new ListenerName(saslMechanism),
                false, saslMechanism, true, null,
                null, null, Time.SYSTEM, new LogContext(), defaultApiVersionsSupplier());
    }
Verify that unparsed broker configs don't break clients. This is to ensure that clients
created by brokers are not broken if broker configs are passed to clients.
clients/src/test/java/org/apache/kafka/common/network/SaslChannelBuilderTest.java