docs: def import_feedin_timeseries(config_data, weather_cell_ids):
      """
      Import RES feed-in time series data and process
  
      Parameters
      ----------
      config_data : dict
          Dictionary containing config data from config files.
      weather_cell_ids : :obj:`list`
          List of weather cell id's (integers) to obtain feed-in data for.
  
      Returns
      -------
      :pandas:`pandas.DataFrame<dataframe>`
          Feedin time series
  
      """
  
      def _retrieve_timeseries_from_oedb(config_data, weather_cell_ids):
          """Retrieve time series from oedb
  
          Parameters
          ----------
          config_data : dict
              Dictionary containing config data from config files.
          weather_cell_ids : :obj:`list`
          List of weather cell id's (integers) to obtain feed-in data for.
  
          Returns
          -------
          :pandas:`pandas.DataFrame<dataframe>`
              Feedin time series
          """
          if config_data['data_source']['oedb_data_source'] == 'model_draft':
              orm_feedin_name = config_data['model_draft']['res_feedin_data']
              orm_feedin = model_draft.__getattribute__(orm_feedin_name)
              orm_feedin_version = 1 == 1
          else:
              orm_feedin_name = config_data['versioned']['res_feedin_data']
              orm_feedin = supply.__getattribute__(orm_feedin_name)
              orm_feedin_version = orm_feedin.version == config_data['versioned']['version']
  
          conn = connection(section=config_data['db_connection']['section'])
          Session = sessionmaker(bind=conn)
          session = Session()
  
          # ToDo: add option to retrieve subset of time series
          # ToDo: find the reference power class for mvgrid/w_id and insert instead of 4
          feedin_sqla = session.query(
              orm_feedin.w_id,
              orm_feedin.source,
              orm_feedin.feedin). \
              filter(orm_feedin.w_id.in_(weather_cell_ids)). \
              filter(orm_feedin.power_class.in_([0, 4])). \
              filter(orm_feedin_version)
  
          feedin = pd.read_sql_query(feedin_sqla.statement,
                                     session.bind,
                                     index_col=['source', 'w_id'])
  
          feedin.sort_index(axis=0, inplace=True)
  
          timeindex = pd.date_range('1/1/2011', periods=8760, freq='H')
  
          recasted_feedin_dict = {}
          for type_w_id in feedin.index:
              recasted_feedin_dict[type_w_id] = feedin.loc[
                                                type_w_id, :].values[0]
  
          feedin = pd.DataFrame(recasted_feedin_dict, index=timeindex)
  
          # rename 'wind_onshore' and 'wind_offshore' to 'wind'
          new_level = [_ if _ not in ['wind_onshore']
                       else 'wind' for _ in feedin.columns.levels[0]]
          feedin.columns.set_levels(new_level, level=0, inplace=True)
  
          feedin.columns.rename('type', level=0, inplace=True)
          feedin.columns.rename('weather_cell_id', level=1, inplace=True)
  
          return feedin
  
      feedin = _retrieve_timeseries_from_oedb(config_data, weather_cell_ids)
  
      return feedin