code: def get_sample(cls):
      np.random.seed(987456)
      nobs, k_vars = 200, 5
      beta = 0.5 * np.array([0.1, 1, 1, 0, 0])
      x = np.random.randn(nobs, k_vars)
      x[:, 0] = 1
      y = np.dot(x, beta) + 2 * np.random.randn(nobs)
      return y, x
  
imports: import os
  import numpy
  import pandas
  import pytest
  from numpy.testing import assert_allclose
  from statsmodels.regression.linear_model import OLS, GLS
  from statsmodels.sandbox.regression.penalized import TheilGLS
label_desc: Use image node_id 1 for calling the CheckEquivalenceMixin obj's underlying member method code with example usage: obj.get_sample(cls) and returns: y,  x