code: def test_ttest(self):
      x1r = self.x1r
      d1w = self.d1w
      assert_almost_equal(
          d1w.ttest_mean(3)[:2], stats.ttest_1samp(x1r, 3), 11
      )
  
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 2 for calling the CheckWeightstats1dMixin obj's underlying member method code with example usage: obj.test_ttest() without return types