docs: def to_vobjects(self, filename, uids=None):
          """Return iCal objects and etags of all Taskwarrior entries in uids
  
          filename -- the Taskwarrior project
          uids -- the UIDs of the Taskwarrior tasks (all if None)
          """
          self._update()
  
          if not uids:
              uids = self.get_uids(filename)
  
          project = basename(filename)
          items = []
  
          for uid in uids:
              vtodos = iCalendar()
              uuid = uid.split('@')[0]
              self._gen_vtodo(self._tasks[project][uuid], vtodos.add('vtodo'))
              items.append((uid, vtodos, '"%s"' % self._tasks[project][uuid]['modified']))
          return items