code: private static BiFunction<AnnotatedValueResolver, ResolverContext, Object>
      resolver(List<RequestObjectResolver> objectResolvers, BeanFactoryId beanFactoryId) {
          return (resolver, ctx) -> {
              Object value = null;
              for (final RequestObjectResolver objectResolver : objectResolvers) {
                  try {
                      value = objectResolver.convert(ctx, resolver.elementType(), beanFactoryId);
                      break;
                  } catch (FallthroughException ignore) {
                      // Do nothing.
                  } catch (Throwable cause) {
                      Exceptions.throwUnsafely(cause);
                  }
              }
              if (value != null) {
                  return value;
              }
              throw new IllegalArgumentException("No suitable request converter found for a @" +
                                                 RequestObject.class.getSimpleName() + " '" +
                                                 resolver.elementType().getSimpleName() + '\'');
          };
      }
docs: Returns a bean resolver which retrieves a value using request converters. If the target element
  is an annotated bean, a bean factory of the specified {@link BeanFactoryId} will be used for creating an
  instance.