code: def test_bse(self):
      # Cannot compare last element of bse because we estimate sigma^2 rather
      # than sigma^2
      bse = self.result.cov_params_approx.diagonal() ** 0.5
      assert_allclose(bse[:-1], self.true["bse_oim"][:-1], atol=1e-7)
  
imports: import os
  import warnings
  import numpy
  from numpy.testing import assert_allclose, assert_raises
  import pandas
  import pytest
  from statsmodels.tsa.regime_switching import markov_switching, markov_regression
label_desc: Use image node_id 5 for calling the TestFedFundsConst obj's underlying member method code with example usage: obj.test_bse() without return types