code: def test_lastfill(self):
      last_fill = LastFill()
      mse_missing = last_fill.evaluate(self.data, 0.1)
      imputed_data = last_fill.impute(self.data)
      assert imputed_data.isna().sum().sum() == 0
      mse = last_fill.evaluate(imputed_data, 0.1)
  
file_path: analytics-zoo/pyzoo/test/zoo/chronos/autots/deprecated/preprocessing/test_fill.py
imports: import numpy
  import pandas
  import pytest
  from test.zoo.pipeline.utils.test_utils import ZooTestCase
  from zoo.chronos.autots.deprecated.feature.time_sequence import TimeSequenceFeatureTransformer
  from zoo.chronos.autots.deprecated.preprocessing.impute.LastFill import LastFill
  from zoo.chronos.autots.deprecated.preprocessing.impute import FillZeroImpute
label_desc: Use image node_id 4 for calling the TestDataImputation obj's underlying member method code with example usage: obj.test_lastfill() without return types