`TryRead` and `TryWrite` are still available for non-blocking reads and writes.

To signify the end of the stream, close the ring buffer from the writer side with `rb.CloseWriter()`

Either side can use `rb.CloseWithError(err error)` to signal an error and close the ring buffer. 
Any reads or writes will return the error on next call.

     *
     * @return an {@link Optional} containing the error stream, or empty if not applicable
     */
    @Nonnull
    Optional<OutputStream> err();

    /**
     * Returns a list of core extensions, if configured in the .mvn/extensions.xml file.
     *
     * @return an {@link Optional} containing the list of core extensions, or empty if not configured
     */

        try {
            parser.parseArgument(args);
        } catch (final CmdLineException e) {
            System.err.println(e.getMessage());
            System.err.println("java " + Crawler.class.getCanonicalName() + " [options...] arguments...");
            parser.printUsage(System.err);
            return;
        }

        if (logger.isDebugEnabled()) {
            try {

              super.publish(record)

              val parameters = record.parameters
              if (sslDebug && record.loggerName == "javax.net.ssl" && parameters != null) {
                System.err.println(parameters[0])
              }
            }
          }

        if (debug) {
          handler.level = Level.ALL
          handler.formatter = OneLineLogFormat()
          val activeLogger = getLogger("")

      if (callback is PasswordCallback) {
        val console = System.console()

        if (console != null) {
          callback.password = console.readPassword(callback.prompt)
        } else {
          System.err.println(callback.prompt)
          callback.password = System.`in`.bufferedReader().readLine().toCharArray()
        }
      } else {
        throw UnsupportedCallbackException(callback)
      }
    }
  }
}

            try ( CloseableIterator<SmbResource> it = smbFile.children() ) {
                while ( it.hasNext() ) {
                    try ( SmbResource serv = it.next() ) {
                        System.err.println(serv.getName());
                    }
                }
            }
        }
        catch ( SmbUnsupportedOperationException e ) {
            Assume.assumeTrue("Browsing unsupported", false);

def _regenerate_error_with_loc(
    *, errors: Sequence[Any], loc_prefix: Tuple[Union[str, int], ...]
) -> List[Dict[str, Any]]:
    updated_loc_errors: List[Any] = [
        {**err, "loc": loc_prefix + err.get("loc", ())}
        for err in _normalize_errors(errors)
    ]

    return updated_loc_errors


def _annotation_is_sequence(annotation: Union[Type[Any], None]) -> bool:

```Python hl_lines="13  15"
{!../../docs_src/custom_request_and_route/tutorial002.py!}
```

Se uma exceção ocorrer, a instância `Request` ainda estará em escopo, então podemos ler e fazer uso do corpo da requisição ao lidar com o erro:

```Python hl_lines="16-18"
{!../../docs_src/custom_request_and_route/tutorial002.py!}
```

## Classe `APIRoute` personalizada em um router

Se você abrir no seu navegador a URL:

```
http://127.0.0.1:8000/items/foo-item
```

... sem adicionar o parâmetro obrigatório `needy`, você verá um erro como:

```JSON
{
    "detail": [
        {
            "loc": [
                "query",
                "needy"
            ],
            "msg": "field required",

                context.topDirectory,
                context.rootDirectory,
                context.parserRequest.in(),
                context.parserRequest.out(),
                context.parserRequest.err(),
                context.extensions,
                getJvmArguments(context.rootDirectory),
                (MavenOptions) context.options);
    }

    protected List<String> getJvmArguments(Path rootDirectory) {