code: def test_default_values(self):
      count = np.array([5, 12])
      nobs = np.array([83, 99])
      stat, pval = smprop.proportions_ztest(count, nobs, value=None)
      assert_almost_equal(stat, -1.4078304151258787)
      assert_almost_equal(pval, 0.15918129181156992)
  
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 2 for calling the TestProportion obj's underlying member method code with example usage: obj.test_default_values() without return types