code: def serialize_message(logger, message: str, variable):
      logger.info(f"gluonts[{message}]: {variable}")
  
file_path: gluonts/src/gluonts/evaluation/backtest.py
imports: import logging
  from typing import Optional, Tuple, Iterator
  import numpy
  import pandas
  from gluonts.dataset.common import DataEntry, Dataset
  from gluonts.dataset.field_names import FieldName
  from gluonts.dataset.split import split
  from gluonts.dataset.stat import calculate_dataset_statistics
  from gluonts.dataset.util import period_index
  from gluonts.evaluation import Evaluator
  from gluonts.model.forecast import Forecast
  from gluonts.model.predictor import Predictor
  from gluonts.itertools import maybe_len
label_desc: Use image node_id 3 for calling a global function with example usage: serialize_message(logger, message, variable) without return types