code: def setup_class(cls):
      rs = np.random.RandomState(1234)
      cls.exog1 = rs.randn(200, 5)
      cls.endog1 = cls.exog1.sum(1) + rs.randn(200)
      cls.weights1 = 1.0 + np.sin(np.arange(200.0) / 100.0 * np.pi)
      cls.exog2 = rs.randn(50, 1)
      cls.endog2 = 0.3 * cls.exog2.ravel() + rs.randn(50)
      cls.weights2 = 1.0 + np.log(np.arange(1.0, 51.0))
  
file_path: statsmodels/statsmodels/regression/tests/test_tools.py
imports: import numpy
  from numpy.testing import assert_allclose
  import pytest
  from statsmodels.regression.linear_model import WLS
  from statsmodels.regression._tools import _MinimalWLS
label_desc: Use image node_id 1 for calling the TestMinimalWLS obj's underlying member method code with example usage: obj.setup_class(cls) without return types