func (v *myProtoValue) keyAsStruct(key string) *myProtoValue {
	if v == nil || v.GetStructValue() == nil {
		return asMyProtoValue(&structpb.Struct{Fields: make(map[string]*structpb.Value)})
	}

	return &myProtoValue{v.GetStructValue().Fields[key]}
}

// asMyProtoValue wraps a protobuf Struct so we may use it with keyAsStruct and keyAsString
func asMyProtoValue(s *structpb.Struct) *myProtoValue {

    public static final String ALL_LANGUAGES = "all";

    public static final String INVALID_NUMERIC_PARAMETER = "-1";

    public static final String FACET_FIELD_PREFIX = "field:";

    public static final String FACET_QUERY_PREFIX = "query:";

    public static final String MATCHES_ALL_QUERY = "*:*";

    @Deprecated

  private class Itr implements Iterator<E> {
    /** Index of element to be returned by next, or a negative number if no such. */
    private int nextIndex;

    /**
     * nextItem holds on to item fields because once we claim that an element exists in hasNext(),
     * we must return it in the following next() call even if it was in the process of being removed
     * when hasNext() was called.
     */

```

/// tip

Pydantic 是 FastAPI 中所有数据验证和序列化的核心，当你在没有设默认值的情况下使用 `Optional` 或 `Union[Something, None]` 时，它具有特殊行为，你可以在 Pydantic 文档中阅读有关<a href="https://docs.pydantic.dev/latest/concepts/models/#required-optional-fields" class="external-link" target="_blank">必需可选字段</a>的更多信息。

///

### 使用Pydantic中的`Required`代替省略号(`...`)

如果你觉得使用 `...` 不舒服，你也可以从 Pydantic 导入并使用 `Required`：

```Python hl_lines="2  8"

	QueueLimit uint64          `json:"queueLimit"`
	Transport  *http.Transport `json:"-"`
	Username   string          `json:"username"`
	Password   string          `json:"password"`
}

// Validate ElasticsearchArgs fields
func (a ElasticsearchArgs) Validate() error {
	if !a.Enable {
		return nil
	}
	if a.URL.IsEmpty() {
		return errors.New("empty URL")
	}
	if a.Format != "" {
		f := strings.ToLower(a.Format)

							key="labels.index_label"
						/></label>
					<div class="col-lg-5 col-md-8 col-sm-7 col-xs-6">
						<la:select property="fields.label" styleId="labelTypeSearchOption" multiple="true" styleClass="form-control">
							<c:forEach var="item" items="${labelTypeItems}">
								<la:option value="${f:u(item.value)}">${f:h(item.label)}</la:option>

type validator struct{}

func checkFields(un *unstructured.Unstructured) error {
	var errs error
	for key := range un.Object {
		if _, ok := validFields[key]; !ok {
			errs = multierror.Append(errs, fmt.Errorf("unknown field %q", key))
		}
	}
	return errs
}

func (v *validator) validateResource(istioNamespace, defaultNamespace string, un *unstructured.Unstructured, writer io.Writer) (validation.Warning, error) {

🗄 `BaseSettings` ⚪️➡️ Pydantic & ✍ 🎧-🎓, 📶 🌅 💖 ⏮️ Pydantic 🏷.

🎏 🌌 ⏮️ Pydantic 🏷, 👆 📣 🎓 🔢 ⏮️ 🆎 ✍, & 🎲 🔢 💲.

👆 💪 ⚙️ 🌐 🎏 🔬 ⚒ & 🧰 👆 ⚙️ Pydantic 🏷, 💖 🎏 📊 🆎 & 🌖 🔬 ⏮️ `Field()`.

```Python hl_lines="2  5-8  11"
{!../../docs_src/settings/tutorial001.py!}
```

/// tip

🚥 👆 💚 🕳 ⏩ 📁 & 📋, 🚫 ⚙️ 👉 🖼, ⚙️ 🏁 1️⃣ 🔛.

///

			} else {
				// Iterating over the partInfos and asserting the fields.
				for j, actualMetaData := range actualResult.Parts {
					//  Asserting the PartNumber in the PartInfo.
					if actualMetaData.PartNumber != expectedResult.Parts[j].PartNumber {

  /** The parts of the domain name, converted to lower case. */
  private final ImmutableList<String> parts;

  /**
   * Cached value of #publicSuffixIndex(). Do not use directly.
   *
   * <p>Since this field isn't {@code volatile}, if an instance of this class is shared across
   * threads before it is initialized, then each thread is likely to compute their own copy of the
   * value.
   */
  @SuppressWarnings("Immutable")