}
```

しかし、クライアントが`http://example.com/items/bar`（存在しない`item_id` `"bar"`）をリクエストした場合、HTTPステータスコード404（"not found"エラー）と以下のJSONレスポンスが返されます:

```JSON
{
  "detail": "Item not found"
}
```

/// tip | 豆知識

`HTTPException`を発生させる際には、`str`だけでなく、JSONに変換できる任意の値を`detail`パラメータとして渡すことができます。

`dict`や`list`などを渡すことができます。

これらは **FastAPI** によって自動的に処理され、JSONに変換されます。

///

## カスタムヘッダーの追加 { #add-custom-headers }

	"github.com/pierrec/lz4/v4"
)

// Max bzip2 concurrency across calls. 50% of GOMAXPROCS.
var bz2Limiter = pbzip2.CreateConcurrencyPool((runtime.GOMAXPROCS(0) + 1) / 2)

func detect(r *bufio.Reader) format {
	z, err := r.Peek(4)
	if err != nil {
		return formatUnknown
	}
	for _, f := range magicHeaders {
		if bytes.Equal(f.header, z[:len(f.header)]) {
			return f.f
		}
	}

items = {"foo": "The Foo Wrestlers"}


@app.get("/items-header/{item_id}")
async def read_item_header(item_id: str):
    if item_id not in items:
        raise HTTPException(
            status_code=404,
            detail="Item not found",
            headers={"X-Error": "There goes my error"},
        )

package tests_test

import (
	"testing"

	"gorm.io/gorm"
)

type Man struct {
	ID     int
	Age    int
	Name   string
	Detail string
}

// Panic-safe BeforeUpdate hook that checks for Changed("age")
func (m *Man) BeforeUpdate(tx *gorm.DB) (err error) {
	if !tx.Statement.Changed("age") {
		return nil
	}
	return nil
}

func TestSubModel(t *testing.T) {
	man := Man{Age: 18, Name: "random-name"}

    /**
     * Attaches [tag] to the request using [T] as a key. Tags can be read from a request using
     * [Request.tag]. Use null to remove any existing tag assigned for [T].
     *
     * Use this API to attach timing, debugging, or other application data to a request so that
     * you may read it in interceptors, event listeners, or callbacks.
     */
    @JvmName("reifiedTag")

    assert response.json() == {"username": "secret"}


def test_security_api_key_no_key():
    response = client.get("/users/me")
    assert response.status_code == 401, response.text
    assert response.json() == {"detail": "Not authenticated"}
    assert response.headers["WWW-Authenticate"] == "APIKey"


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text

# Build execution model

At the highest level, Gradle's execution model is quite simple:

Below is the protocol in some more detail:

1. The client looks for a compatible idle daemon. If there isn't one, it starts a new daemon.
2. The client connects to the idle daemon and sends it a request to do some work. If the daemon is no longer running, the client starts again.

        "-Dorg.gradle.java.installations.auto-download=false",
        "-Porg.gradle.java.installations.auto-download=false",
        "-Dorg.gradle.java.installations.auto-detect=false",
        "-Porg.gradle.java.installations.auto-detect=false",
    ) + os.javaInstallationLocations(arch)

fun promotionBuildParameters(
    dependencyBuildId: RelativeId,
    extraParameters: String,
    gitUserName: String,

      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>build-helper-maven-plugin</artifactId>
        <executions>
          <execution>
            <id>attach-gradle-module-metadata</id>
            <goals>
              <goal>attach-artifact</goal>
            </goals>
            <configuration>
              <artifacts>
                <artifact>
                  <file>target/publish/module.json</file>

            },
            "HTTPValidationError": {
                "title": "HTTPValidationError",
                "type": "object",
                "properties": {
                    "detail": {
                        "title": "Detail",
                        "type": "array",
                        "items": {
                            "$ref": "#/components/schemas/ValidationError"
                        }