code: def retrain_func(
      counter,
      pred_time,
      train_series,
      past_covariates,
      future_covariates,
  ):
      return len(train_series) % 2 == 0
  
imports: import copy
  import itertools
  import os
  import pathlib
  from typing import Callable
  from unittest.mock import Mock, patch
  import numpy
  import pandas
  import pytest
  from darts.datasets import AirPassengersDataset, IceCreamHeaterDataset
  from darts.logging import get_logger
  from darts.metrics import mape
  from darts.models import ARIMA, BATS, FFT, TBATS, VARIMA, AutoARIMA, Croston, ExponentialSmoothing, FourTheta, KalmanForecaster, LinearRegressionModel, NaiveDrift, NaiveMean, NaiveMovingAverage, NaiveSeasonal, NotImportedModule, Prophet, RandomForest, RegressionModel, StatsForecastAutoARIMA, StatsForecastAutoCES, StatsForecastAutoETS, StatsForecastAutoTheta, Theta
  from darts.models.forecasting.forecasting_model import LocalForecastingModel, TransferableFutureCovariatesLocalForecastingModel
  from darts.timeseries import TimeSeries
  from darts.utils import timeseries_generation
  from darts.utils.utils import ModelMode, SeasonalityMode, TrendMode
label_desc: Use image node_id 1 for calling the TestLocalForecastingModels obj's underlying member method code with example usage: obj.retrain_func(counter, pred_time, train_series, past_covariates, future_covariates) and returns: unknown