code: def test_summary(self):
      np.random.seed(34234)
      time = 50 * np.random.uniform(size=200)
      status = np.random.randint(0, 2, 200).astype(np.float64)
      exog = np.random.normal(size=(200, 4))
  
      mod = PHReg(time, exog, status)
      rslt = mod.fit()
      smry = rslt.summary()
  
      strata = np.kron(np.arange(50), np.ones(4))
      mod = PHReg(time, exog, status, strata=strata)
      rslt = mod.fit()
      smry = rslt.summary()
      msg = "3 strata dropped for having no events"
      assert_(msg in str(smry))
  
      groups = np.kron(np.arange(25), np.ones(8))
      mod = PHReg(time, exog, status)
      rslt = mod.fit(groups=groups)
      smry = rslt.summary()
  
      entry = np.random.uniform(0.1, 0.8, 200) * time
      mod = PHReg(time, exog, status, entry=entry)
      rslt = mod.fit()
      smry = rslt.summary()
      msg = "200 observations have positive entry times"
      assert_(msg in str(smry))
  
imports: import itertools
  import os
  import numpy
  from statsmodels.duration.hazard_regression import PHReg
  from numpy.testing import assert_allclose, assert_equal, assert_
  import pandas
  import pytest
  from .results import survival_r_results
  from .results import survival_enet_r_results
label_desc: Use image node_id 10 for calling the TestPHReg obj's underlying member method code with example usage: obj.test_summary() without return types