docs: public static Optional<RDFSyntax> getSyntax(final List<MediaType> acceptableTypes,
              final Optional<String> mimeType) {
          if (acceptableTypes.isEmpty()) {
              // TODO -- JDK9 refactor with Optional::or
              if (mimeType.isPresent()) {
                  return empty();
              }
              return of(TURTLE);
          }
          final Optional<MediaType> mt = mimeType.map(MediaType::valueOf);
          for (final MediaType type : acceptableTypes) {
              if (mt.filter(type::isCompatible).isPresent()) {
                  return empty();
              }
              final Optional<RDFSyntax> syntax = MEDIA_TYPES.stream().filter(type::isCompatible)
                  .findFirst().map(MediaType::toString).flatMap(RDFSyntax::byMediaType);
              if (syntax.isPresent()) {
                  return syntax;
              }
          }
          LOGGER.debug("Valid syntax not found among {} or {}", acceptableTypes, mimeType);
          throw new NotAcceptableException();
      }