code: private static void listRelationships(ProjectFile file)
     {
        for (Task task : file.getTasks())
        {
           System.out.print(task.getID());
           System.out.print('\t');
           System.out.print(task.getName());
           System.out.print('\t');
  
           dumpRelationList(task.getPredecessors());
           System.out.print('\t');
           dumpRelationList(task.getSuccessors());
           System.out.println();
        }
     }
docs: This method lists task predecessor and successor relationships.
  
  @param file project file