How to use the ptr._gen_check_output function in ptr

def test_gen_output(self) -> None:
        test_cmd = ("echo.exe", "''") if ptr.WINDOWS else ("/bin/echo",)

        stdout, stderr = self.loop.run_until_complete(ptr._gen_check_output(test_cmd))
        self.assertTrue(b"\n" in stdout)
        self.assertEqual(stderr, None)

        if ptr.WINDOWS:
            return

        # TODO: Test this on Windows and ensure we capture failures corerctly
        with self.assertRaises(CalledProcessError):
            if ptr.MACOSX:
                false = "/usr/bin/false"
            else:
                false = "/bin/false"

            self.loop.run_until_complete(ptr._gen_check_output((false,)))

stdout, stderr = self.loop.run_until_complete(ptr._gen_check_output(test_cmd))
        self.assertTrue(b"\n" in stdout)
        self.assertEqual(stderr, None)

        if ptr.WINDOWS:
            return

        # TODO: Test this on Windows and ensure we capture failures corerctly
        with self.assertRaises(CalledProcessError):
            if ptr.MACOSX:
                false = "/usr/bin/false"
            else:
                false = "/bin/false"

            self.loop.run_until_complete(ptr._gen_check_output((false,)))