public static void retainMatching(Collection<String> values,
      String... patterns) {
    retainMatching(values, Arrays.asList(patterns));
  }
@Test
  public void testRetainMatchingWithNoPatterns() throws Exception {
    Collection<String> values = stringToList("A");
    StringCollectionUtil.retainMatching(values);
    assertTrue(values.contains("A"));
  }