code: def setup_class(cls):
      formula_outcome = (
          "bweight ~ prenatal1_ + mmarried_ + mage + fbaby_"
      )
      mod = OLS.from_formula(formula_outcome, dta_cat)
      tind = np.asarray(dta_cat["mbsmoke_"])
      cls.teff = TreatmentEffect(mod, tind, results_select=res_probit)
  
file_path: statsmodels/statsmodels/treatment/tests/test_teffects.py
imports: import os
  import numpy
  from numpy.testing import assert_allclose
  import pandas
  import pytest
  from statsmodels.regression.linear_model import OLS
  from statsmodels.discrete.discrete_model import Probit
  from statsmodels.treatment.treatment_effects import TreatmentEffect
  from .results import results_teffects
label_desc: Use image node_id 1 for calling the TestTEffects obj's underlying member method code with example usage: obj.setup_class(cls) without return types