code: def test_llf(self):
      assert_allclose(
          self.result.llf,
          self.true["llf"],
          atol=self.atol,
          rtol=self.rtol,
      )
  
imports: import warnings
  import os
  import numpy
  from numpy.testing import assert_equal, assert_allclose
  import pandas
  import pytest
  from statsmodels.tools import add_constant
  from statsmodels.tsa.regime_switching import markov_autoregression
label_desc: Use image node_id 2 for calling the MarkovAutoregression obj's underlying member method code with example usage: obj.test_llf() without return types