code: private void readRelationships()
     {
        for (MapRow row : m_tables.get("REL"))
        {
           Task predecessor = m_activityMap.get(row.getString("PREDECESSOR_ACTIVITY_ID"));
           Task successor = m_activityMap.get(row.getString("SUCCESSOR_ACTIVITY_ID"));
           if (predecessor != null && successor != null)
           {
              Duration lag = row.getDuration("LAG_VALUE");
              RelationType type = row.getRelationType("LAG_TYPE");
  
              successor.addPredecessor(predecessor, type, lag);
           }
        }
     }
docs: Read task relationships.