@Override
    public HashCode hash() {
      long value = checksum.getValue();
      if (bits == 32) {
        /*
         * The long returned from a 32-bit Checksum will have all 0s for its second word, so the
         * cast won't lose any information and is necessary to return a HashCode of the correct
         * size.
         */
        return HashCode.fromInt((int) value);
      } else {
        return HashCode.fromLong(value);

    public interface ContentTransformer {
        /**
         * Interpolate the value read from the xpp3 document
         *
         * @param source    the source value
         * @param fieldName a description of the field being interpolated. The implementation may use this to
         *                  log stuff
         * @return the interpolated value
         */
        String transform(String source, String fieldName);
    }

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

The `name` parameter is **still required** (not *optional*) because it doesn't have a default value. Still, `name` accepts `None` as the value:

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

The good news is, in most cases, you will be able to simply use `|` to define unions of types:

```python

  @MapFeature.Require(SUPPORTS_REMOVE)
  /*
   * We are comparing Multimaps of the same type, so as long as they have value collections that
   * implement equals() (as with ListMultimap or SetMultimap, as opposed to a QueueMultimap or
   * something), our equality check is value-based.
   */
  @SuppressWarnings("UndefinedEquals")
  public void testRetainAllPropagatesToMultimap() {

  }

  /** Returns the key used to look up this system property. */
  public String key() {
    return key;
  }

  /**
   * Returns the current value for this system property by delegating to {@link
   * System#getProperty(String)}.
   *
   * <p>The value returned by this method is non-null except in rare circumstances:
   *
   * <ul>

     */
    String type() default "java.lang.String";

    /**
     * Specifies the default value of the configuration property.
     *
     * @return the default value as a string, defaults to empty string
     */
    String defaultValue() default "";

    /**
     * Specifies whether the configuration property is read-only.
     *

    public interface ContentTransformer {
        /**
         * Interpolate the value read from the xpp3 document
         *
         * @param source    The source value
         * @param fieldName A description of the field being interpolated. The implementation may use this to
         *                  log stuff.
         * @return The interpolated value.
         */
        String transform(String source, String fieldName);
    }

    the key value sent in the query parameter automatically and provides it as the
    dependency result. But it doesn't define how to send that API key to the client.

    ## Usage

    Create an instance object and use that object as the dependency in `Depends()`.

    The dependency result will be a string containing the key value.

    ## Example

    ```python

constraints.AssertTrue.message = {item} 必须为 true。
constraints.DecimalMax.message = {item} 必须小于 {value}。
constraints.DecimalMin.message = {item} 必须大于 {value}。
constraints.Digits.message = {item} 必须是数字。(预期: <数字>.<数字>)
constraints.Future.message = {item} 必须是未来的值。
constraints.Max.message = {item} 必须小于或等于 {value}。
constraints.Min.message = {item} 必须大于或等于 {value}。
constraints.NotNull.message = {item} 不能为空。
constraints.Null.message = {item} 必须为 null。

constraints.DecimalMax.message = {item} doit être inférieur à {value}.
constraints.DecimalMin.message = {item} doit être supérieur à {value}.
constraints.Digits.message = {item} doit être un nombre. (attendu : <nombre>.<nombre>)
constraints.Future.message = {item} doit être une valeur future.
constraints.Max.message = {item} doit être inférieur ou égal à {value}.
constraints.Min.message = {item} doit être supérieur ou égal à {value}.