code: def test_robust_kurtosis_ab(self):
      # Test custom alpha, beta in kr3
      x = self.kurtosis_x
      alpha, beta = (10.0, 45.0)
      kurtosis = robust_kurtosis(
          self.kurtosis_x, ab=(alpha, beta), excess=False
      )
      num = np.mean(x[x > np.percentile(x, 100.0 - alpha)]) - np.mean(
          x[x < np.percentile(x, alpha)]
      )
      denom = np.mean(x[x > np.percentile(x, 100.0 - beta)]) - np.mean(
          x[x < np.percentile(x, beta)]
      )
      assert_almost_equal(kurtosis[2], num / denom)
  
imports: import numpy
  import pandas
  from numpy.testing import assert_almost_equal, assert_raises, assert_equal, assert_allclose
  from statsmodels.stats._adnorm import normal_ad
  from statsmodels.stats.stattools import omni_normtest, jarque_bera, durbin_watson, _medcouple_1d, medcouple, robust_kurtosis, robust_skewness
label_desc: Use image node_id 21 for calling the TestStattools obj's underlying member method code with example usage: obj.test_robust_kurtosis_ab() without return types