code: protected JSONArray getResponsiveImageSources(Media media) {
      Collection<Rendition> renditions = media.getRenditions();
      JSONArray sources = new JSONArray();
      for (Rendition rendition : renditions) {
        sources.put(toReponsiveImageSource(media, rendition));
      }
      return sources;
    }
docs: Collect responsive JSON metadata for all renditions as image sources.
  @param media Media
  @return JSON metadata