code: def test_formula_args(self):
      np.random.seed(34234)
      n = 200
      time = 50 * np.random.uniform(size=n)
      status = np.random.randint(0, 2, size=n).astype(np.float64)
      exog = np.random.normal(size=(200, 2))
      offset = np.random.uniform(size=n)
      entry = np.random.uniform(0, 1, size=n) * time
  
      df = pd.DataFrame(
          {
              "time": time,
              "status": status,
              "x1": exog[:, 0],
              "x2": exog[:, 1],
              "offset": offset,
              "entry": entry,
          }
      )
      model1 = PHReg.from_formula(
          "time ~ x1 + x2",
          status="status",
          offset="offset",
          entry="entry",
          data=df,
      )
      result1 = model1.fit()
      model2 = PHReg.from_formula(
          "time ~ x1 + x2",
          status=df.status,
          offset=df.offset,
          entry=df.entry,
          data=df,
      )
      result2 = model2.fit()
      assert_allclose(result1.params, result2.params)
      assert_allclose(result1.bse, result2.bse)
  
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 7 for calling the TestPHReg obj's underlying member method code with example usage: obj.test_formula_args() without return types