private String serializeSSPToJson(SystemStreamPartition systemStreamPartition) {
    try {
      return sspMapper.writeValueAsString(systemStreamPartition);
    } catch (IOException e) {
      throw new SamzaException(String.format("Exception occurred when serializing the partition: %s", systemStreamPartition), e);
    }
  }
Serializes the {@param SystemStreamPartition} to json string.
@param systemStreamPartition represents the input system stream partition.
@return the SystemStreamPartition serialized to json.
samza-core/src/main/java/org/apache/samza/container/grouper/task/TaskPartitionAssignmentManager.java