code: private static String createAnnotationCollectionId(Collection<Annotation> annotations) {
          if (annotations.isEmpty())
              return "";
  
          return annotations.stream()
              .sorted(comparing(a -> a.annotationType().getName()))
              .map(CdiSpiHelper::createAnnotationId)
              .collect(joining(",", "[", "]"));
      }
docs: Generates a unique signature for a collection of annotations.