### Question:
Selectors { public static <Input, Output> SelectorFunction<Input, Output> nothing() { return new SelectorFunction<Input, Output>() { @Override public Output select(Input input) { return null; } }; }  @SafeVarargs static SelectorFunction<Input, Output> firstAvailable(@NonNull final SelectorFunction<Input, Output> function,
                                                         final SelectorFunction<Input, Output>... functions); static SelectorFunction<Collection<T>, T> filtered(@NonNull final SelectorFunction<Collection<T>, T> selector,
                                                   @NonNull final Predicate<T> predicate); static SelectorFunction<Collection<T>, T> single(final T preference); static SelectorFunction<Input, Output> nothing();  }### Answer:
@Test public void nothing() throws Exception { String result = Selectors.<Collection<String>, String>nothing() .select(asList("A", "B", "C")); assertNull(result); }