code: def test_fit_efron(rossi, coef_rossi_coxph_efron):
      cph = CoxPHSurvivalAnalysis(ties="efron")
      cph.fit(rossi.x.values, rossi.y)
  
      actual = pd.Series(cph.coef_, index=rossi.x.columns)
      assert_array_almost_equal(
          coef_rossi_coxph_efron.values,
          actual.loc[coef_rossi_coxph_efron.index].values,
      )
  
imports: import warnings
  import numpy
  from numpy.testing import assert_array_almost_equal
  import pandas
  import pytest
  from scipy.optimize import check_grad
  from sklearn.exceptions import ConvergenceWarning
  from sklearn.pipeline import make_pipeline
  from sklearn.preprocessing import StandardScaler
  from sksurv.column import standardize
  from sksurv.datasets import load_breast_cancer
  from sksurv.linear_model.coxph import CoxPHOptimizer, CoxPHSurvivalAnalysis
  from sksurv.preprocessing import OneHotEncoder
label_desc: Use image node_id 6 for calling the TestCoxPH obj's underlying member method code with example usage: obj.test_fit_efron(rossi, coef_rossi_coxph_efron) without return types