class_docstr: ``BaseBackend`` is the base class for all backends.
  All explainability implementations should extend this abstract class
  and implement the methods marked as abstract.
docstr: Create a backend instance using a given implementation.
  
  Parameters
  ----------
  model : any
      Model used.
  preprocessing: category_encoders, ColumnTransformer, list or dict
      The processing apply to the original data.
docstr_tok: ["Create","a","backend","instance","using","a","given","implementation",".","Parameters","--","--","--","--","--","model",":","any","Model","used",".","preprocessing",":","category_encoders",",","ColumnTransformer",",","list","or","dict","The","processing","apply","to","the","original","data","."]
code: def __init__(self, model: Any, preprocessing: Optional[Any] = None):
      """Create a backend instance using a given implementation.
  
      Parameters
      ----------
      model : any
          Model used.
      preprocessing: category_encoders, ColumnTransformer, list or dict
          The processing apply to the original data.
      """
      self.model = model
      self.preprocessing = preprocessing
      self.explain_data: Any = None
      self.state = None
      self._case, self._classes = check_model(model)
      if self._case not in self.supported_cases:
          raise ValueError(
              f"Model not supported by the backend as it does not cover {self._case} case"
          )
  
file_path: shapash/shapash/backend/base_backend.py
imports: from abc import ABC, abstractmethod
  from typing import Any, List, Optional, Union
  import pandas
  import numpy
  from shapash.utils.check import check_model, check_contribution_object
  from shapash.utils.transform import adapt_contributions, get_preprocessing_mapping
  from shapash.utils.utils import choose_state
label_desc: Use image node_id 1 to create a new BaseBackend object from inherited base classes: ABC with example: obj = BaseBackend(model, preprocessing)