code: def test_objectmapper(self):
      df = pdml.ModelFrame([])
      self.assertIs(
          df.covariance.EmpiricalCovariance,
          covariance.EmpiricalCovariance,
      )
      self.assertIs(
          df.covariance.EllipticEnvelope, covariance.EllipticEnvelope
      )
      self.assertIs(df.covariance.GraphLasso, covariance.GraphLasso)
      self.assertIs(df.covariance.GraphLassoCV, covariance.GraphLassoCV)
      self.assertIs(df.covariance.LedoitWolf, covariance.LedoitWolf)
      self.assertIs(df.covariance.MinCovDet, covariance.MinCovDet)
      self.assertIs(df.covariance.OAS, covariance.OAS)
      self.assertIs(
          df.covariance.ShrunkCovariance, covariance.ShrunkCovariance
      )
  
      self.assertIs(
          df.covariance.shrunk_covariance, covariance.shrunk_covariance
      )
      self.assertIs(df.covariance.graph_lasso, covariance.graph_lasso)
  
file_path: pandas-ml/pandas_ml/skaccessors/test/test_covariance.py
imports: import pytest
  import sklearn.datasets
  import sklearn.covariance
  import pandas_ml
  import pandas_ml.util.testing
label_desc: Use image node_id 1 for calling the TestCovariance obj's underlying member method code with example usage: obj.test_objectmapper() without return types