Exemplo de teste utilizando hamcrest e guava para obter apenas os números pares

SampleTest.java

@Test public void testFilterWithPredicatePairNumbers() {
	final List<Integer> numbers = getNumbers();
	final List<Integer> onlyPair = filter(numbers, new Predicate<Integer>() {
		public boolean apply(Integer input) {
			return input % 2 == 0;
		}
	});
	
	assertThat("deveriam vir apenas os numeros pares entre [0-10]", 
		onlyPair, are(2, 4, 6, 8, 10) );
}

private List<Integer> getNumbers() {
	Integer[] array = new Integer[10];
	for (int i = 0; i < array.length; i++) {
		array[i] = i + 1;
	}
	return Lists.newArrayList( array );
}

private List<Integer> filter(List<Integer> numeros, Predicate<Integer> predicate) {
	List<Integer> list = Lists.newArrayList();
	for (Integer numero : numeros) {
		if ( predicate.apply(numero) ) {
			list.add( numero ); 
		}
	}
	return list;
}

public static <T> Matcher<List<? super T>> are(final T... ts) {
    final Collection<?> c1 = Arrays.asList(ts);
    return new BaseMatcher<List<? super T>>() {
        public boolean matches(Object o) {
            Collection<?> c2 = (Collection<?>) o;
            return c1.containsAll(c2) && c2.containsAll(c1);
        }

        public void describeTo(Description description) {
            description.appendText("elements: ");
            description.appendValueList("(", ",", ")", ts);
        }
    };
}

depências maven que utilizei. usei a versão 11.0.2 do guava devido a estar em projeto com java sdk 1.5

<dependency>
    <groupId>org.reflections</groupId>
    <artifactId>reflections</artifactId>
    <version>0.9.9-RC1</version>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.11</version>
</dependency>       
<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>11.0.2</version>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>com.springsource.org.apache.commons.lang</artifactId>
    <version>2.6.0</version>
</dependency>