code: def test_spherical(self):
      cov, nobs = self.cov, self.nobs
      # from Stata 14
      p_chi2 = 0.0006422366870356
      # df = 5
      chi2 = 21.53275509455011
  
      stat, pv = smmv.test_cov_spherical(cov, nobs)
      assert_allclose(stat, chi2, rtol=1e-7)
      assert_allclose(pv, p_chi2, rtol=1e-6)
  
file_path: statsmodels/statsmodels/stats/tests/test_multivariate.py
imports: import numpy
  from numpy.testing import assert_allclose, assert_equal
  from statsmodels.stats import weightstats
  import statsmodels.stats.multivariate
  from statsmodels.stats.multivariate import confint_mvmean_fromstats
  from statsmodels.tools.testing import Holder
label_desc: Use image node_id 2 for calling the TestCovStructure obj's underlying member method code with example usage: obj.test_spherical() without return types