code: def setup_class(cls):
      # computed from data with ``cov = np.cov(dta1, rowvar=0, ddof=1)``
      cls.cov = np.array(
          [
              [
                  28.965925000000002,
                  17.215358333333327,
                  2.6945666666666654,
              ],
              [
                  17.215358333333327,
                  21.452852666666672,
                  6.044527833333332,
              ],
              [
                  2.6945666666666654,
                  6.044527833333332,
                  13.599042333333331,
              ],
          ]
      )
      cls.nobs = 25
  
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 1 for calling the TestCovStructure obj's underlying member method code with example usage: obj.setup_class(cls) without return types