code: def setup_class(cls):
      path = os.path.join(
          current_path, "results", "results_predict_fedfunds.csv"
      )
      results = pd.read_csv(path)
      true = {
          "params": np.r_[
              0.9820939, 0.0503587, 3.70877, 9.556793, 2.107562**2
          ],
          "llf": -508.63592,
          "llf_fit": -508.63592,
          "llf_fit_em": -508.65852,
          "bse_oim": np.r_[
              0.0104002, 0.0268434, 0.1767083, 0.2999889, np.nan
          ],
          "smoothed0": results["const_sm1"],
          "smoothed1": results["const_sm2"],
          "predict0": results["const_yhat1"],
          "predict1": results["const_yhat2"],
          "predict_predicted": results["const_pyhat"],
          "predict_filtered": results["const_fyhat"],
          "predict_smoothed": results["const_syhat"],
      }
      super().setup_class(true, fedfunds, k_regimes=2)
  
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 1 for calling the TestFedFundsConst obj's underlying member method code with example usage: obj.setup_class(cls) without return types