code: def test_objectmapper_undersampling(self):
      import imblearn.under_sampling as us
  
      df = pdml.ModelFrame([])
      self.assertIs(
          df.imbalance.under_sampling.ClusterCentroids,
          us.ClusterCentroids,
      )
      self.assertIs(
          df.imbalance.under_sampling.CondensedNearestNeighbour,
          us.CondensedNearestNeighbour,
      )
      self.assertIs(
          df.imbalance.under_sampling.EditedNearestNeighbours,
          us.EditedNearestNeighbours,
      )
      self.assertIs(
          df.imbalance.under_sampling.RepeatedEditedNearestNeighbours,
          us.RepeatedEditedNearestNeighbours,
      )
      self.assertIs(
          df.imbalance.under_sampling.InstanceHardnessThreshold,
          us.InstanceHardnessThreshold,
      )
      self.assertIs(df.imbalance.under_sampling.NearMiss, us.NearMiss)
      self.assertIs(
          df.imbalance.under_sampling.NeighbourhoodCleaningRule,
          us.NeighbourhoodCleaningRule,
      )
      self.assertIs(
          df.imbalance.under_sampling.OneSidedSelection,
          us.OneSidedSelection,
      )
      self.assertIs(
          df.imbalance.under_sampling.RandomUnderSampler,
          us.RandomUnderSampler,
      )
      self.assertIs(
          df.imbalance.under_sampling.TomekLinks, us.TomekLinks
      )
  
file_path: pandas-ml/pandas_ml/imbaccessors/test/test_imbalance.py
imports: import pytest
  import numpy
  import pandas_ml
  import pandas_ml.util.testing
label_desc: Use image node_id 1 for calling the TestImbalance obj's underlying member method code with example usage: obj.test_objectmapper_undersampling() without return types