///

Наприклад, цей кастомний валідатор перевіряє, чи починається ID елемента з `isbn-` для номера книги <abbr title="International Standard Book Number - Міжнародний стандартний номер книги">ISBN</abbr> або з `imdb-` для ID URL фільму на <abbr title="Internet Movie Database - Інтернетна база даних фільмів: вебсайт з інформацією про фільми">IMDB</abbr>:

    checkResult(zeroForNull, iterable1Null2, "1-0-2");
    checkResult(zeroForNull, iterableFourNulls, "0-0-0-0");
  }

  @SuppressWarnings("AppendIterableIterator") // We intentionally test the Iterator overload.
  private static void checkNoOutput(Joiner joiner, Iterable<? extends @Nullable Integer> set) {
    assertThat(joiner.join(set)).isEqualTo("");

  }

  private interface StringListPredicate extends Predicate<List<String>> {}

  private interface IntegerSupplier extends Supplier<Integer> {}

  // Intentionally duplicate the Predicate interface to test that it won't cause
  // exceptions
  private interface IntegerStringFunction
      extends IntegerSupplier, Predicate<List<String>>, StringListPredicate {}

  }

  private interface StringListPredicate extends Predicate<List<String>> {}

  private interface IntegerSupplier extends Supplier<Integer> {}

  // Intentionally duplicate the Predicate interface to test that it won't cause
  // exceptions
  private interface IntegerStringFunction
      extends IntegerSupplier, Predicate<List<String>>, StringListPredicate {}

          override fun encode(
            writer: DerWriter,
            value: String,
          ) = writer.writeUtf8(value)
        },
    )

  /**
   * Based on International Alphabet No. 5. Note that there are bytes that IA5 and US-ASCII
   * disagree on interpretation.
   *
   * TODO(jwilson): constrain to IA5 characters.
   */
  val IA5_STRING =
    BasicDerAdapter(

  ({{{./xref/org/apache/maven/model/inheritance/DefaultInheritanceAssembler.html}source}}).

  By default, every model field is inherited as-is from parent, with a few exceptions that are intentionally not inherited:
  <<<modelVersion>>>, <<<artifactId>>>, <<<packaging>>>, <<<profiles>>> (injected in phase 1) and <<<prerequisites>>>.

      implements Serializable {
    private static final AlwaysEqual INSTANCE = new AlwaysEqual();

    @Override
    @SuppressWarnings("UnusedVariable") // intentionally weird Comparator
    public int compare(@Nullable Object o1, @Nullable Object o2) {
      return 0;
    }

    @Override
    public String toString() {
      return "ALWAYS_EQUAL";
    }

///

Например, эта кастомная проверка убеждается, что ID элемента начинается с `isbn-` для номера книги <abbr title="International Standard Book Number - Международный стандартный книжный номер">ISBN</abbr> или с `imdb-` для ID URL фильма на <abbr title="Internet Movie Database - Интернетная база данных фильмов: веб‑сайт с информацией о фильмах">IMDB</abbr>:

/// tip | 提示

Pydantic 也有 [`BeforeValidator`](https://docs.pydantic.dev/latest/concepts/validators/#field-before-validator) 等等。🤓

///

例如，以下自訂驗證器會檢查項目 ID 是否以 `isbn-` 開頭（<abbr title="International Standard Book Number - 國際標準書號">ISBN</abbr> 書籍編號），或以 `imdb-` 開頭（<abbr title="Internet Movie Database - 互聯網電影資料庫: 含有電影資訊的網站">IMDB</abbr> 電影 URL 的 ID）：

        allOptionalSelectors.addAll(projectActivation.getOptionalActiveProjectSelectors());
        allOptionalSelectors.addAll(projectActivation.getRequiredActiveProjectSelectors());
        // We intentionally ignore the results of this method.
        // As a side effect it will log the optional projects that could not be resolved.