code: def test_warnings(self):
      rng = np.random.default_rng(
          189117774084579816190295271136455278291
      )
  
      res = stats.dunnett(
          *self.samples_3, control=self.control_3, random_state=rng
      )
      msg = r"Computation of the confidence interval did not converge"
      with pytest.warns(UserWarning, match=msg):
          res._allowance(tol=1e-5)
  
file_path: scipy/scipy/stats/tests/test_multicomp.py
imports: import copy
  import numpy
  import pytest
  from numpy.testing import assert_allclose
  from scipy import stats
  from scipy.stats._multicomp import _pvalue_dunnett, DunnettResult
label_desc: Use image node_id 7 for calling the TestDunnett obj's underlying member method code with example usage: obj.test_warnings() without return types