code: def setup_class(cls):
      np.random.seed(9876789)
      n1, n2 = 20, 30
      m1, m2 = 1, 1.2
      x1 = m1 + np.random.randn(n1, 3)
      x2 = m2 + np.random.randn(n2, 3)
      w1 = np.random.randint(1, 4, n1)
      w2 = np.random.randint(1, 4, n2)
  
      cls.x1, cls.x2 = x1, x2
      cls.w1, cls.w2 = w1, w2
      cls.d1w = DescrStatsW(x1, weights=w1, ddof=0)
      cls.d2w = DescrStatsW(x2, weights=w2, ddof=1)
      cls.x1r = cls.d1w.asrepeats()
      cls.x2r = cls.d2w.asrepeats()
  
imports: import numpy
  from scipy import stats
  import pandas
  from numpy.testing import assert_, assert_almost_equal, assert_allclose
  from statsmodels.stats.weightstats import DescrStatsW, CompareMeans, ttest_ind, ztest, zconfint
  from statsmodels.tools.testing import Holder
label_desc: Use image node_id 1 for calling the TestWeightstats2d_nobs obj's underlying member method code with example usage: obj.setup_class(cls) without return types