code: def test_medcouple_symmetric(self):
      mc = medcouple(np.arange(5.0))
      assert_almost_equal(mc, 0)
  
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 4 for calling the TestStattools obj's underlying member method code with example usage: obj.test_medcouple_symmetric() without return types