@Nullable
    @Override
    public Boolean isResponseStreaming(Type returnType, @Nullable MediaType contentType) {
        final Class<?> clazz = typeToClass(unwrapUnaryAsyncType(returnType));
        if (clazz == null) {
            return null;
        }

        if (HttpResponse.class.isAssignableFrom(clazz)) {
            return true;
        }
        if (Publisher.class.isAssignableFrom(clazz) || Stream.class.isAssignableFrom(clazz)) {
            return false;
        }

        return null;
    }
A response converter implementation which creates an {@link HttpResponse} with
the objects published from a {@link Publisher} or {@link Stream}.
core/src/main/java/com/linecorp/armeria/internal/server/annotation/AggregatedResponseConverterFunction.java