@Test
public void testFilter() {

    final APredicateNoThrow<String> len1 = new APredicateNoThrow<String>() {
        @Override  public boolean apply(String o) {
            return o.length() == 1;
        }
    };
    assertEquals(Arrays.<String>asList(), ACollectionHelper.filter(Arrays.<String>asList(), len1));
    assertEquals(Arrays.<String>asList(), ACollectionHelper.filter (Arrays.asList ("abc"), len1));
    assertEquals (Arrays.asList ("a"), ACollectionHelper.filter (Arrays.asList ("a"), len1));
    assertEquals(Arrays.asList("a", "d"), ACollectionHelper.filter(Arrays.asList("a", "bc", "d", "efg"), len1));
}