@GwtIncompatible("java.util.regex.Pattern")
  public void doesNotContainMatch(@Nullable Pattern regex) {
    checkNotNull(regex);
    if (actual == null) {
      failWithActual("expected a string that does not contain a match for", regex);
      return;
    }
    Matcher matcher = regex.matcher(actual);
    if (matcher.find()) {
      failWithoutActual(
          fact("expected not to contain a match for", regex),
          fact("but contained", matcher.group()),
          fact("full string", actualCustomStringRepresentationForPackageMembersToCall()));
    }
  }
@Test
  public void stringDoesNotContainMatchStringUsesFindFailNull() {
    expectFailureWhenTestingThat(null).doesNotContainMatch("[b]");
    assertFailureValue("expected a string that does not contain a match for", "[b]");
  }