@Nullable
    @Override
    public MultipartRemovalStrategy defaultMultipartRemovalStrategy() {
        final String multipartRemovalStrategy = getNormalized("defaultMultipartRemovalStrategy");
        if (multipartRemovalStrategy == null) {
            return null;
        }
        switch (multipartRemovalStrategy) {
            case "never":
                return MultipartRemovalStrategy.NEVER;
            case "on_response_completion":
                return MultipartRemovalStrategy.ON_RESPONSE_COMPLETION;
            default:
                throw new IllegalArgumentException(
                        multipartRemovalStrategy + " isn't a MultipartRemovalStrategy");
        }
    }
Implementation of {@link FlagsProvider} which provides values from JVM options to {@link Flags}.
core/src/main/java/com/linecorp/armeria/common/SystemPropertyFlagsProvider.java