* would be the right tool for the job here: {@code @Nullable} is the annotation that we're trying
   * to get rid of, and {@code @NonNull} would be wrong for our use case for the same reason as
   * {@code requireNonNull}: Our use case is the one in which {@code T} has parametric nullness—and
   * thus its value may be legitimately {@code null}.)
   */
  @ParametricNullness
  @SuppressWarnings("nullness")

func getUserWithProvider(ctx context.Context, userProvider, user string, validate bool) (string, error) {
	switch userProvider {
	case madmin.BuiltinProvider:
		if validate {
			if _, ok := globalIAMSys.GetUser(ctx, user); !ok {
				return "", errNoSuchUser
			}
		}
		return user, nil
	case madmin.LDAPProvider:
		if globalIAMSys.GetUsersSysType() != LDAPUsersSysType {
			return "", errIAMActionNotAllowed
		}

}

// Send a payload to the remote server.
func (s *Stream) Send(b []byte) error {
	if s.Requests == nil {
		return errors.New("stream does not accept requests")
	}
	select {
	case s.Requests <- b:
		return nil
	case <-s.ctx.Done():
		return context.Cause(s.ctx)
	}
}

// Results returns the results from the remote server one by one.
// If any error is returned by the callback, the stream will be canceled.

		switch len(parts) {
		default:
			t.Errorf("%s:%d: unable to understand comments: %s", input, lineno, line)
		case 1:
			// no comment
		case 2:
			// might be printed form or hex
			note := strings.TrimSpace(parts[1])
			if isHexes(note) {
				hexes = note
			} else {
				printed = note
			}
		case 3:
			// printed form, then hex
			printed = strings.TrimSpace(parts[1])
			hexes = strings.TrimSpace(parts[2])

	_ = w.w.CloseWithError(err)
	_ = w.r.CloseWithError(err)
	w.err = err
}

func (w *writerAt) Close() (err error) {
	switch {
	case len(w.buffer) > 0:
		err = errors.New("some file segments were not flushed from the queue")
		_ = w.w.CloseWithError(err)
	case w.err != nil:
		// No need to close here since both pipes were
		// closing inside TransferError()
		err = w.err
	default:
		err = w.w.Close()
	}

     * @throws ArtifactInstallerException in case of an error
     * @throws IllegalArgumentException in case {@code request} is {@code null}
     */
    void install(@Nonnull ArtifactInstallerRequest request);

    /**
     * @param session the repository session
     * @param artifact the {@link ProducedArtifact} to install
     * @throws ArtifactInstallerException in case of an error which can be a given artifact cannot be found or the

     * before they are sorted and actual build execution starts.
     *
     * @param session the Maven session
     * @throws MavenExecutionException in case of issue
     */
    public void afterProjectsRead(MavenSession session) throws MavenExecutionException {
        // do nothing
    }

    /**
     * Invoked after MavenSession instance has been created.
     *

E você também pode declarar parâmetros de corpo como opcionais, definindo o valor padrão com `None`:

{* ../../docs_src/body_multiple_params/tutorial001_an_py310.py hl[18:20] *}

/// note | Nota

Repare que, neste caso, o `item` que seria capturado a partir do corpo é opcional. Visto que ele possui `None` como valor padrão.

///

## Múltiplos parâmetros de corpo { #multiple-body-parameters }

	if cnt > 0 {
		for i := range last {
			entry := lastN[(cnt+i)%last]
			if (entry == log.Info{}) {
				continue
			}
			select {
			case subCh <- entry:
			case <-doneCh:
				return nil
			}
		}
	}
	return sys.pubsub.Subscribe(madmin.LogMaskAll, subCh, doneCh, filter)
}

// Init if HTTPConsoleLoggerSys is valid, always returns nil right now

    @Override
    public void setRootLoggerLevel(Level level) {
        String value =
                switch (level) {
                    case DEBUG -> "debug";
                    case INFO -> "info";
                    case ERROR -> "error";
                };

        String current = System.setProperty(Constants.MAVEN_LOGGER_DEFAULT_LOG_LEVEL, value);