code: def __init__(
      self,
      dataset_manager: DatasetManager,
      cache_dir: Optional[str] = None,
  ):
      self._dataset_manager = dataset_manager
      self._cache_dir = cache_dir
  
imports: import logging
  import os
  from typing import Optional
  from ludwig.constants import CHECKSUM, META, TEST, TRAINING, VALIDATION
  from ludwig.data.cache.types import alphanum, CacheableDataset
  from ludwig.data.cache.util import calculate_checksum
  from ludwig.data.dataset.base import DatasetManager
  from ludwig.utils import data_utils
  from ludwig.utils.fs_utils import delete, path_exists
label_desc: Use image node_id 1 to create a new CacheManager object  with example: obj = CacheManager(dataset_manager, cache_dir)