code: def test_chdtriv(self):
      _assert_inverts(
          sp.chdtriv,
          lambda v, x: mpmath.gammainc(
              v / 2, b=x / 2, regularized=True
          ),
          0,
          [ProbArg(), IntArg(1, 100)],
          rtol=1e-4,
      )
  
imports: import itertools
  import numpy
  from numpy.testing import assert_equal, assert_allclose
  import pytest
  import scipy.special
  from scipy.special._testutils import MissingModule, check_version, FuncData
  from scipy.special._mptestutils import Arg, IntArg, get_args, mpf2float, assert_mpmath_equal
label_desc: Use image node_id 12 for calling the TestCDFlib obj's underlying member method code with example usage: obj.test_chdtriv() without return types