code: def test_results(self):
      stata_results = np.array(
          [158.7504, 321.7482, 75.45371, -238.4515]
      )
      stata_results_pooled = np.array([158.7504, 130.8095, 27.94091])
      endow, coef, inter, gap = self.model.three_fold().params
      unexp, exp, gap = self.model.two_fold().params
      np.testing.assert_almost_equal(gap, stata_results[0], 3)
      np.testing.assert_almost_equal(endow, stata_results[1], 3)
      np.testing.assert_almost_equal(coef, stata_results[2], 3)
      np.testing.assert_almost_equal(inter, stata_results[3], 3)
  
      np.testing.assert_almost_equal(gap, stata_results_pooled[0], 3)
      np.testing.assert_almost_equal(exp, stata_results_pooled[1], 3)
      np.testing.assert_almost_equal(unexp, stata_results_pooled[2], 3)
  
imports: import numpy
  from statsmodels.datasets.ccard.data import load_pandas
  from statsmodels.stats.oaxaca import OaxacaBlinder
  from statsmodels.tools.tools import add_constant
label_desc: Use image node_id 2 for calling the TestOaxacaNoConstPassed obj's underlying member method code with example usage: obj.test_results() without return types