code: def _get_optimizer_and_scheduler(
      self, optimizer, scheduler, num_epochs, sub_train
  ):
      if optimizer is None or scheduler is None:
          (
              optimizer,
              scheduler,
          ) = self._initialize_optimizer_and_scheduler(
              optimizer, scheduler, num_epochs, sub_train, self.lr
          )
      return optimizer, scheduler
  
imports: import logging
  import warnings
  from abc import abstractmethod
  from functools import partial
  from pathlib import Path
  from small_text.classifiers.classification import Classifier
  from small_text.integrations.pytorch.exceptions import PytorchNotFoundError
  from small_text.training.early_stopping import EarlyStopping, NoopEarlyStopping, EarlyStoppingOrCondition
  from small_text.training.metrics import Metric
  from small_text.training.model_selection import ModelSelection, NoopModelSelection
  from small_text.utils.classification import empty_result, prediction_result
label_desc: Use image node_id 10 for calling the PytorchClassifier obj's underlying member method code with example usage: obj._get_optimizer_and_scheduler(optimizer, scheduler, num_epochs, sub_train) and returns: optimizer,  scheduler