code: def add_station(self, lv_station):
          
          if not isinstance(lv_station, LVStationDing0):
              raise Exception('Given LV station is not a LVStationDing0 object.')
          if self._station is None:
              self._station = lv_station
              self.graph_add_node(lv_station)
              self.grid_district.lv_load_area.mv_grid_district.mv_grid.graph_add_node(lv_station)
docs: Adds a LV station to _station and grid graph if not already existing