* expected to be unequal. For example:
 *
 * {@snippet :
 * EquivalenceTester.of(someStringEquivalence)
 *     .addEquivalenceGroup("hello", "h" + "ello")
 *     .addEquivalenceGroup("world", "wor" + "ld")
 *     .test();
 * }
 *
 * <p>Note that testing {@link Object#equals(Object)} is more simply done using the {@link

{* ../../docs_src/custom_response/tutorial009c_py39.py hl[9:14,17] *}

Statt:

```json
{"message": "Hello World"}
```

... wird die Response jetzt Folgendes zurückgeben:

```json
{
  "message": "Hello World"
}
```

Natürlich werden Sie wahrscheinlich viel bessere Möglichkeiten finden, Vorteil daraus zu ziehen, als JSON zu formatieren. 😉

input size | lib | MB/s | Allocated
--- | --- | --- | ---
regular | standard | 97 | 3.6MB
regular | jstream | 175 | 2.1MB
large | standard | 92 | 305MB
large | jstream | 404 | 69MB

In a real world scenario, including initialization and reader overhead from varying blob sizes, performance can be expected as below:

{* ../../docs_src/custom_response/tutorial009c_py39.py hl[9:14,17] *}

Теперь вместо того, чтобы возвращать:

```json
{"message": "Hello World"}
```

...этот ответ вернёт:

```json
{
  "message": "Hello World"
}
```

Разумеется, вы наверняка найдёте гораздо более полезные способы воспользоваться этим, чем просто форматирование JSON. 😉

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">

  public void testWrap() {
    new EqualsTester()
        .addEqualityGroup(
            LENGTH_EQUIVALENCE.wrap("hello"),
            LENGTH_EQUIVALENCE.wrap("hello"),
            LENGTH_EQUIVALENCE.wrap("world"))
        .addEqualityGroup(LENGTH_EQUIVALENCE.wrap("hi"), LENGTH_EQUIVALENCE.wrap("yo"))
        .addEqualityGroup(
            LENGTH_EQUIVALENCE.<@Nullable String>wrap(null),

Create a file `main.py` with:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">

### 创建

* 创建一个 `main.py` 文件并写入以下内容:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">

            package org.apache.maven.samples.sample;

            public class App {
                public static void main(String... args) {
                    System.out.println("Hello World!");
                }
            }
            """;

    protected Map<String, String> invoke(Path cwd, Path userHome, Collection<String> goals, Collection<String> args)
            throws Exception {

	errFatal(local.RegisterStreamingHandler(handlerTest2, h2))

	// local to remote
	remoteConn := local.Connection(remoteHost)
	errFatal(remoteConn.WaitForConnect(t.Context()))
	const testPayload = "Hello Grid World!"

	gotResp := make(chan struct{})
	go func() {
		start := time.Now()
		t.Log("Roundtrip: sending request")
		resp, err := remoteConn.Request(t.Context(), handlerTest, []byte(testPayload))