code: private NavigableSet<RenditionMetadata> rotateSourceRenditions(Set<RenditionMetadata> candidates) {
      if (rotation == null) {
        return new TreeSet<>(candidates);
      }
      return candidates.stream()
          .map(rendition -> new VirtualTransformedRenditionMetadata(rendition.getRendition(),
              rotateMapWidth(rendition.getWidth(), rendition.getHeight()),
              rotateMapHeight(rendition.getWidth(), rendition.getHeight()),
              null, rotation))
          .collect(Collectors.toCollection(TreeSet::new));
    }
docs: Rotates all source renditions if configured.
  @param candidates Candidate renditions
  @return Virtual-rotated and sorted candidate renditions