code: def test_gdtrib(self):
      # Use small values of a and x or mpmath doesn't converge
      _assert_inverts(
          sp.gdtrib,
          lambda a, b, x: mpmath.gammainc(b, b=a * x, regularized=True),
          1,
          [
              Arg(0, 1e2, inclusive_a=False),
              ProbArg(),
              Arg(0, 1e3, inclusive_a=False),
          ],
          rtol=1e-5,
      )
  
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 7 for calling the TestCDFlib obj's underlying member method code with example usage: obj.test_gdtrib() without return types