constraints.LuhnCheck.message = The Luhn Modulo 11 checksum of {value} is incorrect.
constraints.Mod10Check.message = The Modulo 10 checksum of {value} is incorrect.
constraints.Mod11Check.message = The Modulo 11 checksum of {value} is incorrect.
constraints.ModCheck.message = The {modType} checksum of {value} is incorrect.
constraints.NotBlank.message = {item} is required.
constraints.NotEmpty.message = {item} is required.

constraints.LuhnCheck.message = The Luhn Modulo 11 checksum of {value} is incorrect.
constraints.Mod10Check.message = The Modulo 10 checksum of {value} is incorrect.
constraints.Mod11Check.message = The Modulo 11 checksum of {value} is incorrect.
constraints.ModCheck.message = The {modType} checksum of {value} is incorrect.
constraints.NotBlank.message = {item} is required.
constraints.NotEmpty.message = {item} is required.

- OkHttp is a small and light dependency.  Don't introduce new dependencies or major new functionality.
- OkHttp targets the intersection of RFC correct *and* widely implemented.  Incorrect implementations that are very widely implemented e.g. a bug in Apache, Nginx, Google, Firefox should also be handled.

Before your code can be accepted into the project you must also sign the

    initMapWithNullValue();
    testToString_formatting();
  }

  @CollectionFeature.Require(absent = NON_STANDARD_TOSTRING)
  public void testToString_formatting() {
    assertEquals(
        "map.toString() incorrect", expectedToString(getMap().entrySet()), getMap().toString());
  }

  private String expectedToString(Set<Entry<K, V>> entries) {
    Map<K, V> reference = new LinkedHashMap<>();
    for (Entry<K, V> entry : entries) {

        .addEqualityGroup(Functions.constant("incorrect"))
        .addEqualityGroup(Functions.toStringFunction())
        .addEqualityGroup(g)
        .testEquals();

    new EqualsTester()
        .addEqualityGroup(g, Functions.<@Nullable Object>constant(null))
        .addEqualityGroup(Functions.constant("incorrect"))
        .addEqualityGroup(Functions.toStringFunction())

    initMapWithNullValue();
    testToString_formatting();
  }

  @CollectionFeature.Require(absent = NON_STANDARD_TOSTRING)
  public void testToString_formatting() {
    assertEquals(
        "map.toString() incorrect", expectedToString(getMap().entrySet()), getMap().toString());
  }

  private String expectedToString(Set<Entry<K, V>> entries) {
    Map<K, V> reference = new LinkedHashMap<>();
    for (Entry<K, V> entry : entries) {

  public void testSetCountConditional_negativeOldCount_addUnsupported() {
    try {
      assertSetCountNegativeOldCount();
    } catch (UnsupportedOperationException tolerated) {
    }
  }

  // Incorrect expected present count.

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCountConditional_oldCountTooLarge() {
    assertFalse(
        "setCount() with a too-large oldCount should return false",

  public void testSetCountConditional_negativeOldCount_addUnsupported() {
    try {
      assertSetCountNegativeOldCount();
    } catch (UnsupportedOperationException tolerated) {
    }
  }

  // Incorrect expected present count.

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSetCountConditional_oldCountTooLarge() {
    assertFalse(
        "setCount() with a too-large oldCount should return false",

is shorter than ",notConfirmed:"Input values could not be confirmed",badDomain:"Incorrect domain value",badUrl:"The input value is not a correct URL",badCustomVal:"The input value is incorrect",andSpaces:" and spaces ",badInt:"The input value was not a correct number",badSecurityNumber:"Your social security number was incorrect",badUKVatAnswer:"Incorrect UK VAT Number",badUKNin:"Incorrect UK NIN",badUKUtr:"Incorrect UK UTR Number",badStrength:"The password isn't strong enough",badNumberOfSelectedOptionsStart:"You...

  @CollectionFeature.Require(value = KNOWN_ORDER, absent = NON_STANDARD_TOSTRING)
  public void testToString_sizeSeveral() {
    String expected = copyToList(getOrderedElements()).toString();
    assertEquals("collection.toString() incorrect", expected, collection.toString());
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  public void testToString_null() {
    initCollectionWithNullElement();