暫時採用這個（外部開發者）的視角，有助於讓你更直覺地決定該把參數、body 的 Pydantic 模型、response 的模型等放在哪裡，對於那個「外部 API」會更清楚。

///

### 建立一個回呼用的 `APIRouter` { #create-a-callback-apirouter }

先建立一個新的 `APIRouter`，用來放一個或多個回呼。

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[1,23] *}

### 建立回呼的「路徑操作」 { #create-the-callback-path-operation }

要建立回呼的「路徑操作」，就使用你上面建立的同一個 `APIRouter`。

它看起來就像一般的 FastAPI「路徑操作」：

 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>) caching utilities.
 *
 * <p>The core interface used to represent caches is {@link Cache}. In-memory caches can be
 * configured and created using {@link CacheBuilder}, with cache entries being loaded by {@link
 * CacheLoader}. Statistics about cache performance are exposed using {@link CacheStats}.
 *
 * <p>See the Guava User Guide article on <a

 */

package com.google.common.collect.testing;

import static com.google.common.collect.testing.Helpers.copyToList;

import com.google.common.annotations.GwtIncompatible;
import java.util.List;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests a
 * ConcurrentNavigableMap implementation.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible
public class ConcurrentNavigableMapTestSuiteBuilder<K, V>

    /**
     * The target class.
     */
    private final Class<?> targetClass;

    /**
     * The name of the field.
     */
    private final String fieldName;

    /**
     * Creates a {@link FieldNotFoundRuntimeException}.
     *
     * @param targetClass
     *            Target class
     * @param fieldName
     *            Field name
     */

 *
 * @author mbechler
 */
public class EmptyIterator implements CloseableIterator<SmbResource> {

    /**
     * Default constructor for EmptyIterator.
     * Creates an empty iterator with no elements.
     */
    public EmptyIterator() {
        // Default constructor
    }

    /**
     * {@inheritDoc}
     *
     * @see java.util.Iterator#hasNext()
     */

 *
 * This class implements the SAMR CloseHandle operation for releasing
 * Security Account Manager (SAM) handles.
 */
public class MsrpcSamrCloseHandle extends samr.SamrCloseHandle {

    /**
     * Creates a new request to close a SAM handle.
     *
     * @param policyHandle the policy handle to close
     */
    public MsrpcSamrCloseHandle(final rpc.policy_handle policyHandle) {
        super(policyHandle);

package org.apache.maven.api.di;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;

import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * Denotes that a bean should be created as a singleton instance.
 * <p>
 * Singleton-scoped beans are instantiated once and reused throughout the entire
 * Maven execution. This scope should be used for stateless services or components

package org.apache.maven.lifecycle;

/**
 * Signals a failure to locate a lifecycle.
 *
 */
public class LifecycleNotFoundException extends Exception {

    private final String lifecycleId;

    /**
     * Creates a new exception to indicate that the specified lifecycle is unknown.
     *
     * @param lifecycleId The identifier of the lifecycle that could not be located, may be {@code null}.
     */

## Випадок використання { #use-case }

Наприклад, уявімо, що ви хочете за замовчуванням повертати код статусу HTTP «OK» `200`.

Але якщо даних не існувало, ви хочете створити їх і повернути код статусу HTTP «CREATED» `201`.

Водночас ви все одно хочете мати змогу фільтрувати та перетворювати повернені дані за допомогою `response_model`.

Для таких випадків ви можете використати параметр `Response`.

    /** Serial version UID for serialization */
    private static final long serialVersionUID = 1L;

    /** Type of the invalid access token */
    private final String type;

    /**
     * Creates a new InvalidAccessTokenException with the specified type and message.
     *
     * @param type the type of the invalid access token
     * @param message the detailed error message
     */