class_docstr: Loads data and creates class instance ot be tested
class_docstr_tok: ["Loads","data","and","creates","class","instance","ot","be","tested"]
code: def setup_class(cls):
      data = stackloss.load()
      data.exog = add_constant(data.exog)
      cls.res1 = OLS(data.endog, data.exog).fit()
      cls.res2 = RegressionResults()
  
imports: from numpy.testing import assert_almost_equal
  import pytest
  from statsmodels.datasets import stackloss
  from statsmodels.regression.linear_model import OLS
  from statsmodels.tools import add_constant
  from .results.el_results import RegressionResults
label_desc: Use image node_id 1 for calling the GenRes obj's underlying member method code with example usage: obj.setup_class(cls) without return types