BitSet bitset = new BitSet();
    matcher.setBits(bitset);
    for (int i = Character.MIN_VALUE; i <= Character.MAX_VALUE; i++) {
      assertEquals(matcher.matches((char) i), bitset.get(i));
    }
  }

  public void testEmpty() throws Exception {
    doTestEmpty(CharMatcher.any());
    doTestEmpty(CharMatcher.none());
    doTestEmpty(is('a'));
    doTestEmpty(isNot('a'));

因此，我們可以不必把這些都加在每個路徑操作上，而是把它們加在 `APIRouter` 上。

{* ../../docs_src/bigger_applications/app_an_py310/routers/items.py hl[5:10,16,21] title["app/routers/items.py"] *}

由於每個路徑操作的路徑都必須以 `/` 開頭，例如：

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

...所以 prefix 末尾不能帶有 `/`。

因此，此處的 prefix 是 `/items`。

我們也可以加上一個 `tags` 清單，以及會套用在此 router 內所有路徑操作上的額外 `responses`。

 * near enough users to justify the costs.
 *
 * Fortunately, if anyone does want to use a Converter as a `Function<@Nullable A, @Nullable B>`,
 * it's easy to get one: `converter::convert`.
 *
 * [*] In annotating this class, we're ignoring LegacyConverter.
 */
public abstract class Converter<A, B> implements Function<A, B> {
  private final boolean handleNullAutomatically;

        return new InnerInterpolator() {
            @Override
            public String interpolate(String value) {
                if (value != null && value.contains("${")) {
                    String c = cache.get(value);
                    if (c == null) {
                        try {
                            c = interpolator.interpolate(value, recursionInterceptor);
                        } catch (InterpolationException e) {

Comme le chemin de chaque *chemin d'accès* doit commencer par `/`, comme dans :

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

... le préfixe ne doit pas inclure un `/` final.

Ainsi, le préfixe dans ce cas est `/items`.

{* ../../docs_src/bigger_applications/app_an_py310/routers/items.py hl[5:10,16,21] title["app/routers/items.py"] *}

Como el path de cada *path operation* tiene que empezar con `/`, como en:

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

...el prefijo no debe incluir un `/` final.

Así que, el prefijo en este caso es `/items`.

{* ../../docs_src/bigger_applications/app_an_py310/routers/items.py hl[5:10,16,21] title["app/routers/items.py"] *}

Como o path de cada *operação de rota* tem que começar com `/`, como em:

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

...o prefixo não deve incluir um `/` final.

Então, o prefixo neste caso é `/items`.

		// "X-Amz-Algorithm", "X-Amz-Credential", "X-Amz-Signature", " X-Amz-Date", "X-Amz-SignedHeaders", "X-Amz-Expires".
		// If these params are missing its expected to get ErrInvalidQueryParams .
		// In the following test case 2 out of 6 query params are missing.
		{
			inputQueryKeyVals: []string{
				"X-Amz-Algorithm", "",
				"X-Amz-Credential", "",
				"X-Amz-Signature", "",

{* ../../docs_src/bigger_applications/app_an_py310/routers/items.py hl[5:10,16,21] title["app/routers/items.py"] *}

각 *path operation*의 경로는 다음처럼 `/`로 시작해야 하므로:

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

...prefix에는 마지막 `/`가 포함되면 안 됩니다.

따라서 이 경우 prefix는 `/items`입니다.

    int classNameEnd = filename.length() - CLASS_FILE_NAME_EXTENSION.length();
    return filename.substring(0, classNameEnd).replace('/', '.');
  }

  // TODO(benyu): Try java.nio.file.Paths#get() when Guava drops JDK 6 support.
  @VisibleForTesting
  static File toFile(URL url) {
    checkArgument(url.getProtocol().equals("file"));
    try {