code: def update_pareto_optimal_tuples(self, new_label):
          
          assert (isinstance(new_label, LabelTime))
          if self._labels:
              assert (new_label.departure_time <= self._labels[-1].departure_time)
              best_later_departing_arrival_time = self._labels[-1].arrival_time_target
          else:
              best_later_departing_arrival_time = float('inf')
  
          walk_to_target_arrival_time = new_label.departure_time + self._walk_to_target_duration
  
          best_arrival_time = min(walk_to_target_arrival_time,
                                  best_later_departing_arrival_time,
                                  new_label.arrival_time_target)
          # this should be changed to get constant time insertions / additions
          # (with time-indexing)
          if (new_label.arrival_time_target < walk_to_target_arrival_time and
                  new_label.arrival_time_target < best_later_departing_arrival_time):
              self._labels.append(LabelTime(new_label.departure_time, best_arrival_time))
              return True
          else:
              return False
docs: Parameters
          ----------
          new_label: LabelTime
  
          Returns
          -------
          updated: bool