public static ObjectMapper getOldDeserForSSpKeyObjectMapper() {
    ObjectMapper mapper = new ObjectMapper();
    mapper.configure(DeserializationFeature.WRAP_EXCEPTIONS, false);
    mapper.configure(SerializationFeature.WRAP_EXCEPTIONS, false);
    SimpleModule module = new SimpleModule("SamzaModule", new Version(1, 0, 0, ""));

    module.addKeyDeserializer(SystemStreamPartition.class, new OldSystemStreamPartitionKeyDeserializer());
    mapper.registerModules(module, new Jdk8Module());
    return mapper;
  }
Builds {@link ObjectNode} which matches the {@link JobModel} built in setup.
samza-core/src/test/java/org/apache/samza/serializers/model/TestSamzaObjectMapper.java