code: def tune_batch_size(
      self, evaluator_cls: Type[BatchSizeEvaluator], dataset_len: int
  ) -> int:
      return FALLBACK_BATCH_SIZE
  
file_path: ludwig/ludwig/backend/deepspeed.py
imports: from typing import Any, Dict, Optional, Type
  import deepspeed
  from ludwig.backend.base import DataParallelBackend
  from ludwig.constants import FALLBACK_BATCH_SIZE
  from ludwig.distributed import init_dist_strategy
  from ludwig.utils.batch_size_tuner import BatchSizeEvaluator
label_desc: Use image node_id 4 for calling the DeepSpeedBackend obj's underlying member method code with example usage: obj.tune_batch_size(evaluator_cls, dataset_len) and returns: FALLBACK_BATCH_SIZE