public static Thread daemonThread(Runnable r, Class<?> context, String description) {
        return daemonThread(r, "hollow", context, description);
    }
@Test
    public void nullPlatform() {
        try {
            daemonThread(() -> {}, null, getClass(), "boom");
            fail("expected an exception");
        } catch (NullPointerException e) {
            assertEquals("platform required", e.getMessage());
        }
    }