@Nullable
    static MediaType toMediaType(@Nullable MimeType mimeType) {
        if (mimeType == null) {
            return null;
        }
        final MediaType mediaType = MediaType.create(mimeType.getType(), mimeType.getSubtype());
        final Map<String, String> parameters = mimeType.getParameters();
        if (parameters.isEmpty()) {
            return mediaType;
        }
        return mediaType.withParameters(
                parameters.entrySet()
                          .stream()
                          .collect(toImmutableMap(Map.Entry::getKey,
                                                  entry -> ImmutableSet.of(entry.getValue()))));
    }
{@link HttpService} to handle a {@link WebOperation}. Mostly inspired by reactive implementation in
{@link AbstractWebFluxEndpointHandlerMapping}.
spring/boot3-actuator-autoconfigure/src/main/java/com/linecorp/armeria/spring/actuate/WebOperationService.java