Ambos são equivalentes e, por baixo, são a mesma coisa, mas eu recomendaria `Union` em vez de `Optional` porque a palavra "opcional" sugere que o valor é opcional; na verdade, significa "pode ser `None`", mesmo quando não é opcional e continua sendo obrigatório.

Acho que `Union[SomeType, None]` é mais explícito quanto ao significado.

É apenas uma questão de palavras e nomes. Mas essas palavras podem influenciar como você e sua equipe pensam sobre o código.

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Mock witness service for integration testing.
 * Simulates a basic witness service that can accept registrations
 * and send notifications.
 */
public class MockWitnessService implements AutoCloseable {
    private static final Logger log = LoggerFactory.getLogger(MockWitnessService.class);

    private ServerSocket serverSocket;

			Optional:    true,
			Type:        "string",
			Sensitive:   true,
		},
		config.HelpKV{
			Key:         BatchSize,
			Description: "Number of events per HTTP send to webhook target",
			Optional:    true,
			Type:        "number",
		},
		config.HelpKV{
			Key:         QueueSize,
			Description: "configure channel queue size for webhook targets",
			Optional:    true,

                    final Smb2SetInfoRequest treq = new Smb2SetInfoRequest(th.getConfig(), fh.getFileId());
                    treq.setFileInformation(new FileEndOfFileInformation(0));
                    th.send(treq, RequestParam.NO_RETRY);
                }
            }
        } catch (final CIFSException e) {
            throw SmbException.wrap(e);
        }
    }

<h3 id="chan">Channel communication</h3>

<p>
Channel communication is the main method of synchronization
between goroutines.  Each send on a particular channel
is matched to a corresponding receive from that channel,
usually in a different goroutine.
</p>

<p class="rule">
A send on a channel is synchronized before the completion of the
corresponding receive from that channel.
</p>

<p>
This program:
</p>

check your OS is [supported](https://www.elastic.co/support/matrix#show_os).
If it is not, the issue is likely to be closed.

For security vulnerabilities please only send reports to ******@****.***.
See https://www.elastic.co/community/security for more information.

Please fill in the following details to help us reproduce the bug:
-->

     */
    protected Curl() {
        // nothing
    }

    /**
     * Creates a new CurlRequest with the HTTP GET method for the specified URL.
     *
     * @param url the URL to send the GET request to
     * @return a CurlRequest object configured with the GET method and the specified URL
     */
    public static CurlRequest get(final String url) {
        return new CurlRequest(Method.GET, url);
    }

        }

        int r, n;
        final SmbComReadAndXResponse response = new SmbComReadAndXResponse(b, off);
        do {
            r = len > readSize ? readSize : len;
            file.send(new SmbComReadAndX(file.fid, fp, r, null), response);
            n = response.dataLength;
            if (n <= 0) {
                return (int) (fp - start > 0L ? fp - start : -1);
            }
            fp += n;

					perDiskLimit:   opts.Limit,
					minDisks:       listingQuorum,
					reportNotFound: false,
					agreed:         send,
					partial: func(entries metaCacheEntries, _ []error) {
						entry, ok := entries.resolve(&resolver)
						if ok {
							send(*entry)
						}
					},
					finished: nil,
				}

				if err := listPathRaw(ctx, lopts); err != nil {

		opts.Storage = true
		opts.OS = true
		// Older mc - cannot deal with more types...
	}
	return opts, err
}

// TraceHandler - POST /minio/admin/v3/trace
// ----------
// The handler sends http trace to the connected HTTP client.
func (a adminAPIHandlers) TraceHandler(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	// Validate request signature.