code: private static void listSlack(ProjectFile file)
     {
        for (Task task : file.getTasks())
        {
           System.out.println(task.getName() + " Total Slack=" + task.getTotalSlack() + " Start Slack=" + task.getStartSlack() + " Finish Slack=" + task.getFinishSlack());
        }
     }
docs: List the slack values for each task.
  
  @param file ProjectFile instance