class_docstr: LastFill imputation
code: def impute(self, input_df):
      from bigdl.nano.utils.common import invalidInputError
  
      invalidInputError(
          self.imputer is not None, "imputer cannot be empty"
      )
      df = self.imputer.impute(input_df)
      return df
  
file_path: BigDL/python/chronos/src/bigdl/chronos/autots/deprecated/preprocessing/impute/impute.py
imports: from bigdl.chronos.autots.deprecated.preprocessing.impute.abstract import BaseImputation
  from bigdl.chronos.autots.deprecated.preprocessing.impute.LastFill import LastFill
  from bigdl.chronos.utils import deprecated
label_desc: Use image node_id 2 for calling the LastFillImpute obj's underlying member method code with example usage: obj.impute(input_df) and returns: df