public static Find find(String regex) {
    return find(regex, 0);
  }
@Test
  @Category(NeedsRunner.class)
  public void testFindNone() {
    PCollection<String> output = p.apply(Create.of("a", "b", "c", "d")).apply(Regex.find("[xyz]"));

    PAssert.that(output).empty();
    p.run();
  }