class_docstr: Test that the labels are correctly set in the summary table
class_docstr_tok: ["Test","that","the","labels","are","correctly","set","in","the","summary","table"]
code: def setup_class(cls):
      y = [1, 1, 4, 2] * 4
      x = add_constant([1, 2, 3, 4] * 4)
      cls.mod = OLS(endog=y, exog=x).fit()
  
file_path: statsmodels/statsmodels/iolib/tests/test_summary2.py
imports: import warnings
  import numpy
  import pandas
  import pytest
  from numpy.testing import assert_equal
  from statsmodels.iolib.summary2 import summary_col
  from statsmodels.tools.tools import add_constant
  from statsmodels.regression.linear_model import OLS
label_desc: Use image node_id 1 for calling the TestSummaryLabels obj's underlying member method code with example usage: obj.setup_class(cls) without return types