'Compile the 0-argument *pyfunc* with the given *flags*, and check
it returns the same result as the pure Python function.
The got and expected results are returned.'

def run_nullary_func(self, pyfunc, flags):

    cr = compile_isolated(pyfunc, (), flags=flags)
    cfunc = cr.entry_point
    expected = pyfunc()
    got = cfunc()
    self.assertPreciseEqual(got, expected)
    return (got, expected)
