private String presentations(SkysailResponse<List<?>> skysailResponse) {
    Set<String> mediaTypes = new HashSet<String>();
    List<ConverterHelper> registeredConverters = Engine.getInstance().getRegisteredConverters();
    for (ConverterHelper ch : registeredConverters) {
      List<VariantInfo> variants = ch.getVariants(skysailResponse.getClass());
      if (variants == null) {
        continue;
      }
      for (VariantInfo variantInfo : variants) {
        mediaTypes.add(variantInfo.getMediaType().getSubType());
      }
    }

    StringBuilder sb = new StringBuilder();
    sb.append("<ul>\n");
    for (String mediaType : mediaTypes) {
      sb.append("<li><a href='?media=").append(mediaType).append("'>");
      sb.append(mediaType).append("</a></li>\n");
    }

    // sb.append("<li><a href='?media=json'>Json</a></li>\n");
    sb.append("</ul>\n");
    return sb.toString();
  }