code: def test_left_truncated_simple3():
      time_enter = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 9])
      time_exit = np.array([11, 12, 13, 14, 15, 16, 17, 18, 19, 19])
      event = np.array([0, 1, 0, 0, 1, 1, 1, 1, 0, 1], dtype=bool)
  
      x, y, km_ci = kaplan_meier_estimator(
          event, time_exit, time_enter, conf_type="log-log"
      )
  
      true_x = np.concatenate((np.arange(1, 10), np.arange(11, 20)))
      assert_array_almost_equal(x, true_x)
  
      true_y = np.array(
          [
              1,
              0.888889,
              0.888889,
              0.888889,
              0.740741,
              0.592593,
              0.444444,
              0.296296,
              0.148148,
          ]
      )
      assert_array_almost_equal(y[9:], true_y)
  
      true_ci = np.array(
          [
              [
                  1.0,
                  0.432965,
                  0.432965,
                  0.432965,
                  0.289212,
                  0.185919,
                  0.103865,
                  0.043129,
                  0.00736,
              ],
              [
                  1.0,
                  0.983564,
                  0.983564,
                  0.983564,
                  0.929976,
                  0.849818,
                  0.747981,
                  0.624575,
                  0.475977,
              ],
          ]
      )
      assert_array_almost_equal(km_ci[:, :9], np.ones((2, 9)))
      assert_array_almost_equal(km_ci[:, 9:], true_ci)
  
imports: from os.path import dirname, join
  import numpy
  from numpy.testing import assert_array_almost_equal, assert_array_equal
  import pandas
  import pytest
  from sksurv.nonparametric import CensoringDistributionEstimator, SurvivalFunctionEstimator, kaplan_meier_estimator, nelson_aalen_estimator
  from sksurv.testing import FixtureParameterFactory
  from sksurv.util import Surv
label_desc: Use image node_id 13 for calling the TestKaplanMeier obj's underlying member method code with example usage: obj.test_left_truncated_simple3() without return types