# Body - Nested Models { #body-nested-models }

With **FastAPI**, you can define, validate, document, and use arbitrarily deeply nested models (thanks to Pydantic).

## List fields { #list-fields }

You can define an attribute to be a subtype. For example, a Python `list`:

{* ../../docs_src/body_nested_models/tutorial001_py310.py hl[12] *}

This will make `tags` be a list, although it doesn't declare the type of the elements of the list.

 * This class is used to encapsulate the header information for HTTP requests.
 * It provides methods to get and set the name and value of the header,
 * as well as a method to validate the header.
 *
 * <p>Example usage:</p>
 * <pre>
 *     RequestHeader header = new RequestHeader("Content-Type", "application/json");
 *     String name = header.getName();
 *     String value = header.getValue();

	}

	data := r.Reader
	// Validate input data size and it can never be less than zero.
	if data.Size() < -1 {
		bugLogIf(ctx, errInvalidArgument, logger.ErrorKind)
		return pi, toObjectErr(errInvalidArgument)
	}

	uploadIDPath := er.getUploadIDDir(bucket, object, uploadID)
	// Validates if upload ID exists.
	fi, _, err := er.checkUploadIDExists(ctx, bucket, object, uploadID, true)

import okhttp3.Response
import okhttp3.internal.http.RealInterceptorChain

/**
 * Opens a connection to the target server and proceeds to the next interceptor. The network might
 * be used for the returned response, or to validate a cached response with a conditional GET.
 */
object ConnectInterceptor : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Interceptor.Chain): Response {

     * @return The HTML response.
     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse threaddump(final EditForm form) {
        verifyCrudMode(form.crudMode, CrudMode.DETAILS);
        validate(form, messages -> {}, this::asDetailsHtml);
        verifyToken(this::asDetailsHtml);
        final String id = form.id;
        crawlingInfoService.getCrawlingInfo(id).ifPresent(entity -> {
            try {

		}
		return false, azureToObjectError(err, az.Bucket, az.Prefix)
	}

	return len(resp.Segment.BlobItems) > 0, nil
}

type azureConf struct {
	madmin.TierAzure
}

func (conf azureConf) Validate() error {
	switch {
	case conf.AccountName == "":
		return errors.New("the account name is required")

}

// Wrapper for calling PutObject tests for both Erasure multiple disks and single node setup.
func TestObjectAPIPutObjectSingle(t *testing.T) {
	ExecExtendedObjectLayerTest(t, testObjectAPIPutObject)
}

// Tests validate correctness of PutObject.
func testObjectAPIPutObject(obj ObjectLayer, instanceType string, t TestErrHandler) {
	// Generating cases for which the PutObject fails.
	bucket := "minio-bucket"
	object := "minio-object"

* Validate **các cấu trúc phức tạp**:
    * Sử dụng các models Pydantic phân tầng, `List` và `Dict` của Python `typing`,...
    * Và các validators cho phép các cấu trúc dữ liệu phức tạp trở nên rõ ràng và dễ dàng để định nghĩa, kiểm tra và tài liệu hóa thành JSON Schema.
    * Bạn có thể có các object **JSON lồng nhau** và tất cả chúng đã validate và annotated.
* **Có khả năng mở rộng**:

Extra-Schlüssel, die `Field` überreicht werden, werden auch im resultierenden OpenAPI-Schema Ihrer Anwendung gelistet. Da diese Schlüssel nicht notwendigerweise Teil der OpenAPI-Spezifikation sind, könnten einige OpenAPI-Tools, wie etwa [der OpenAPI-Validator](https://validator.swagger.io/), nicht mit Ihrem generierten Schema funktionieren.

///

## Zusammenfassung

Sie können Pydantics `Field` verwenden, um zusätzliche Validierungen und Metadaten für Modellattribute zu deklarieren.

import com.vanniktech.maven.publish.JavadocJar
import com.vanniktech.maven.publish.KotlinJvm

plugins {
  kotlin("jvm")
  id("org.jetbrains.dokka")
  id("com.vanniktech.maven.publish.base")
  id("binary-compatibility-validator")
}

project.applyOsgi(
  "Export-Package: okhttp3.java.net.cookiejar",
  "Automatic-Module-Name: okhttp3.java.net.cookiejar",
  "Bundle-SymbolicName: com.squareup.okhttp3.java.net.cookiejar"
)

dependencies {