code: def from_json(self, params):
      if params is not None:
          self._na_fill_method = params.get("fill_method", None)
          self._na_fill_params = params.get("fill_params", {})
          self._datetime_columns = params.get("datetime_columns", [])
          for col in self._datetime_columns:
              self._na_fill_params[col] = pd.to_datetime(
                  self._na_fill_params[col]
              )
      else:
          self._na_fill_method, self._na_fill_params = None, None
          self._datetime_columns = []
  
file_path: mljar-supervised/supervised/preprocessing/preprocessing_missing.py
imports: import json
  import os
  import numpy
  import pandas
  from supervised.preprocessing.preprocessing_utils import PreprocessingUtils
label_desc: Use image node_id 9 for calling the PreprocessingMissingValues obj's underlying member method code with example usage: obj.from_json(params) without return types