code: private void readRelationship(Link link)
     {
        Task sourceTask = m_taskIdMap.get(link.getSourceTaskID());
        Task destinationTask = m_taskIdMap.get(link.getDestinationTaskID());
        if (sourceTask != null && destinationTask != null)
        {
           Duration lag = getDuration(link.getLagUnit(), link.getLag());
           RelationType type = link.getType();
           Relation relation = destinationTask.addPredecessor(sourceTask, type, lag);
           relation.setUniqueID(link.getID());
        }
     }
docs: Read a task relationship.
  
  @param link ConceptDraw PROJECT task link