### Question:
Checks { public static <S, T extends Iterable<S>> T returnOrThrowIfContainsNull(T iterable) { return orThrowIf( iterable, any(iterable, equalTo(null)), nullPointerFactory()); }  static T returnOrThrowIfNull(T value, NullaryFunction<? extends RuntimeException> exceptionFactory); static T returnOrThrowIfEmpty(
            T value, NullaryFunction<? extends RuntimeException> exceptionFactory); static T returnOrThrowIfContainsNull(T iterable);  }### Answer:
@Test public void shouldReturnIfContainsNoNullsCheckIsSuppliedEmptyIterable() throws Exception { Iterable<Integer> input = iterable(); Iterable<Integer> output = Checks.returnOrThrowIfContainsNull(input); assertThat(output, is(input)); }
@Test(expected = NullPointerException.class) public void shouldThrowANullPointerExceptionIfIterableSuppliedToContainsNoNullsCheckIsNull() throws Exception { Iterable<Integer> input = null; Checks.returnOrThrowIfContainsNull(input); }