class_docstr: Usage of that class makes sense only if you have table data.
  Stores/loads `DataPreprocessor`'s encoders and imputers for pipelines to decrease optional preprocessing time.
  
  :param cache_dir: path to the place where cache files should be stored.
code: def __init__(self, cache_dir: Optional[str] = None):
      super().__init__(PreprocessingCacheDB(cache_dir))
  
file_path: FEDOT/fedot/core/caching/preprocessing_cache.py
imports: from typing import TYPE_CHECKING, Optional, Union
  from fedot.core.caching.base_cache import BaseCache
  from fedot.core.caching.preprocessing_cache_db import PreprocessingCacheDB
label_desc: Use image node_id 1 to create a new PreprocessingCache object from inherited base classes: BaseCache with example: obj = PreprocessingCache(cache_dir)