@Test
public void testEntryTee() {

    final CompletableFuture<String> future = new CompletableFuture<>();
    final Map.Entry<String, Boolean> entry = toEntry("foo", false);
    final boolean boolResult = Stream.of(entry)
            .map(entryTee((key, value) -> future.complete(key)))
            .map(Map.Entry::getValue)
            .findFirst().orElse(true);
    assertFalse("test value", boolResult);
    assertEquals("key is correct", "foo", future.getNow(""));
}