docstr: Saves the feature extractor as a pickle file.
  
  Args:
      path (str): The path to save the file
docstr_tok: ["Saves","the","feature","extractor","as","a","pickle","file",".","Args",":","path","(","str",")",":","The","path","to","save","the","file"]
code: def save_as_object_file(self, path):
      """Saves the feature extractor as a pickle file.
  
      Args:
          path (str): The path to save the file
      """
      if not self._mapping:
          raise ValueError(
              "`fit` method must be called before `save_as_object_file`."
          )
      pickle.dump(self.__dict__, open(path, "wb"))
  
file_path: pytorch_tabular/src/pytorch_tabular/feature_extractor.py
imports: from collections import defaultdict
  import pandas
  from rich.progress import track
  from sklearn.base import BaseEstimator, TransformerMixin
  from pytorch_tabular.models import NODEModel, TabNetModel
  from pytorch_tabular.models.mixture_density import MDNModel
  import torch
label_desc: Use image node_id 5 for calling the DeepFeatureExtractor obj's underlying member method code with example usage: obj.save_as_object_file(path) without return types