code: private void writeRelationList(String fieldName, Object value) throws IOException
     {
        @SuppressWarnings("unchecked")
        List<Relation> list = (List<Relation>) value;
        if (!list.isEmpty())
        {
           m_writer.writeStartList(fieldName);
           for (Relation relation : list)
           {
              m_writer.writeStartObject(null);
              writeIntegerField("task_unique_id", relation.getTargetTask().getUniqueID());
              writeDurationField("lag", relation.getLag());
              writeStringField("type", relation.getType());
              m_writer.writeEndObject();
           }
           m_writer.writeEndList();
        }
     }
docs: Write a relation list field to the JSON file.
  
  @param fieldName field name
  @param value field value