and those default values won't be included in the response, only the values actually set.

So, if you send a request to that *path operation* for the item with ID `foo`, the response (not including default values) will be:

```JSON
{
    "name": "Foo",
    "price": 50.2
}
```

/// info

You can also use:

* `response_model_exclude_defaults=True`
* `response_model_exclude_none=True`

   * and will be really slow if we regress the fix for that.
   */
  @Test
  fun `reading a large part with small byteCount`() {
    val multipartBody =
      MultipartBody
        .Builder("foo")
        .addPart(
          headersOf("header-name", "header-value"),
          object : RequestBody() {
            override fun contentType() = "application/octet-stream".toMediaTypeOrNull()

		t.Fatal(err)
	}
	hdr, err := FileInfoHeader(fileinfo, "")
	if err != nil {
		t.Fatalf("os.Stat: %v", err)
	}
	contents := strings.Repeat(" ", int(hdr.Size))

	hdr.Xattrs = map[string]string{
		"foo": "foo",
		"bar": "bar",
		"baz": "baz",
		"qux": "qux",
	}

	var buf bytes.Buffer
	writer := NewWriter(&buf)
	if err := writer.WriteHeader(hdr); err != nil {
		t.Fatal(err)
	}

### 第三步：建立一個「路徑操作」 { #step-3-create-a-path-operation }

#### 路徑 { #path }

這裡的「路徑」指的是 URL 中自第一個 `/` 以後的部分。

例如，在 URL 中：

```
https://example.com/items/foo
```

……的路徑將會是：

```
/items/foo
```

/// info

「路徑」也常被稱為「端點 endpoint」或「路由 route」。

///

在建置 API 時，「路徑」是分離「關注點」和「資源」的主要方式。

#### 操作 { #operation }

這裡的「操作」指的是 HTTP 的「方法」之一。

  but line comments i.e `// ...` are.
* Negative boolean expressions must use the form `foo == false` instead of
  `!foo` for better readability of the code. This is enforced via
  Checkstyle. Conversely, you should not write e.g. `if (foo == true)`, but
  just `if (foo)`.

#### Editor / IDE Support

IntelliJ IDEs can

   * it.
   *
   * <p>Example:
   *
   * {@snippet :
   * public void useStreamNicely() throws IOException {
   *   SomeStream stream = new SomeStream("foo");
   *   boolean threw = true;
   *   try {
   *     // ... code which does something with the stream ...
   *     threw = false;
   *   } finally {
   *     // If an exception occurs, rethrow it only if threw==false:

#### Path { #path }

"Path" aquí se refiere a la última parte de la URL empezando desde la primera `/`.

Así que, en una URL como:

```
https://example.com/items/foo
```

...el path sería:

```
/items/foo
```

/// info | Información

Un "path" también es comúnmente llamado "endpoint" o "ruta".

///

#### Chemin { #path }

« Chemin » fait ici référence à la dernière partie de l’URL à partir du premier `/`.

Donc, dans une URL telle que :

```
https://example.com/items/foo
```

... le chemin serait :

```
/items/foo
```

/// info

Un « chemin » est aussi couramment appelé « endpoint » ou « route ».

///

#### Path { #path }

"Path" aqui se refere à última parte da URL, começando do primeiro `/`.

Então, em uma URL como:

```
https://example.com/items/foo
```

...o path seria:

```
/items/foo
```

/// info | Informação

Um "path" também é comumente chamado de "endpoint" ou de "rota".

///

  }

  public void testAsSet_absentIsImmutable() {
    Set<Object> absentAsSet = Optional.absent().asSet();
    assertThrows(UnsupportedOperationException.class, () -> absentAsSet.add("foo"));
  }

  public void testTransform_absent() {
    assertEquals(Optional.absent(), Optional.absent().transform(Functions.identity()));