code: def _scan_footpaths(self, stop_id, walk_departure_time):
          
          for _, neighbor, data in self._walk_network.edges_iter(nbunch=[stop_id], data=True):
              d_walk = data["d_walk"]
              arrival_time = walk_departure_time + d_walk / self._walk_speed
              self._update_stop_label(neighbor, arrival_time)
docs: Scan the footpaths originating from stop_id
  
          Parameters
          ----------
          stop_id: int