@Test
public void testVoidToNothing1() throws Exception {

    final String sentinel = "sentinel";
    final CompletableFuture<String> latch = new CompletableFuture<>();
    final Consumer<String> consumer = latch::complete;
    final Nothing nothing = Nothing.voidToNothing1(consumer).apply(sentinel);
    assertTrue("future should be done: " + latch, latch.isDone());
    assertSame("nothing should be returned", Nothing.instance, nothing);
    assertSame("latched should be same as input", sentinel, latch.get());
}