code: def test_empirical_covariance(self):
      iris = datasets.load_iris()
      df = pdml.ModelFrame(iris)
  
      result = df.covariance.empirical_covariance()
      expected = covariance.empirical_covariance(iris.data)
      self.assertIsInstance(result, pdml.ModelFrame)
      tm.assert_index_equal(result.index, df.data.columns)
      tm.assert_index_equal(result.columns, df.data.columns)
      self.assert_numpy_array_almost_equal(result.values, expected)
  
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 2 for calling the TestCovariance obj's underlying member method code with example usage: obj.test_empirical_covariance() without return types