code: def test_score_confint_koopman_nam():
      # example Koopman, based on Nam 1995
  
      x0, n0 = 16, 80
      x1, n1 = 36, 40
      # x = x0 + x1
      # n = n0 + n1
      # p0 = x0 / n0
      # p1 = x1 / n1
  
      results_nam = Holder()
      results_nam.p0_roots = [0.1278, 0.2939, 0.4876]
      results_nam.conf_int = [2.940, 7.152]
  
      res = smprop._confint_riskratio_koopman(
          x1, n1, x0, n0, alpha=0.05
      )
  
      assert_allclose(res._p_roots, results_nam.p0_roots, atol=4)
      assert_allclose(res.confint, results_nam.conf_int, atol=3)
  
      table = [67, 9, 7, 16]  # [67, 7, 9, 16]
      resp = smprop._confint_riskratio_paired_nam(table, alpha=0.05)
      # TODO: currently regression test, need verified results
      ci_old = [0.917832, 1.154177]
      assert_allclose(resp.confint, ci_old, atol=3)
  
imports: import warnings
  import numpy
  from numpy.testing import assert_allclose, assert_almost_equal, assert_array_less, assert_equal, assert_raises
  import pandas
  import pytest
  import statsmodels.stats.proportion
  from statsmodels.stats.proportion import confint_proportions_2indep, multinomial_proportions_confint, power_proportions_2indep, proportion_confint, samplesize_proportions_2indep_onetail, score_test_proportions_2indep
  from statsmodels.tools.sm_exceptions import HypothesisTestWarning
  from statsmodels.tools.testing import Holder
  from statsmodels.stats.tests.results.results_proportion import res_binom, res_binom_methods
label_desc: Use image node_id 21 for calling a global function with example usage: test_score_confint_koopman_nam() without return types