code: def tasks(self):
          
          if self._tasks is None:
              self._tasks = self.parent.tasks.tasks(
                  tasklist="@default", showCompleted="true", showHidden="true",
                  completedMin=self.since, completedMax=self.until)
          log.info(u"NB TASKS {0}".format(len(self._tasks)))
          return self._tasks
docs: All completed tasks within specified time range