def invert(self, a, b):
        s, t, h = self.gcdex(a, b)

        if self.is_one(h):
            return s % b
        else:
            raise NotInvertible("zero divisor")
Tests that unprovided private functions don't cause a missing provide.
dataset/ETHPy150Open sympy/sympy/sympy/polys/domains/ring.py/Ring.invert--crossover with--dataset/ETHPy150Open google/closure-linter/closure_linter/closurizednamespacesinfo_test.py/ClosurizedNamespacesInfoTest.testGetMissingProvides_privatefunction