code: def setup_class(cls):
      d2 = macrodata.load_pandas().data
      g_gdp = 400 * np.diff(np.log(d2["realgdp"].values))
      g_inv = 400 * np.diff(np.log(d2["realinv"].values))
      exogg = add_constant(
          np.c_[g_gdp, d2["realint"][:-1].values], prepend=False
      )
  
      mod1 = GLSAR(g_inv, exogg, 1)
      cls.res = mod1.iterative_fit(5)
  
      from .results.macro_gr_corc_stata import results
  
      cls.results = results
  
file_path: statsmodels/statsmodels/regression/tests/test_glsar_stata.py
imports: import numpy
  from numpy.testing import assert_almost_equal, assert_allclose, assert_equal
  from statsmodels.regression.linear_model import GLSAR
  from statsmodels.tools.tools import add_constant
  from statsmodels.datasets import macrodata
label_desc: Use image node_id 1 for calling the TestGLSARCorc obj's underlying member method code with example usage: obj.setup_class(cls) without return types