code: def filter(self, datasource_type, datasource_id, column):
          
          # TODO: Cache endpoint by user, datasource and column
          datasource = ConnectorRegistry.get_datasource(
              datasource_type, datasource_id, db.session)
          if not datasource:
              return json_error_response(DATASOURCE_MISSING_ERR)
          security_manager.assert_datasource_permission(datasource)
          payload = json.dumps(
              datasource.values_for_column(
                  column,
                  config.get('FILTER_SELECT_ROW_LIMIT', 10000),
              ),
              default=utils.json_int_dttm_ser)
          return json_success(payload)
docs: Endpoint to retrieve values for specified column.
  
          :param datasource_type: Type of datasource e.g. table
          :param datasource_id: Datasource id
          :param column: Column name to retrieve values for
          :return: