docs: public MediaType withParameter(String attribute, String value) {
      checkNotNull(attribute);
      checkNotNull(value);
      String normalizedAttribute = normalizeToken(attribute);
      ImmutableListMultimap.Builder<String, String> builder = ImmutableListMultimap.builder();
      for (Entry<String, String> entry : parameters.entries()) {
        String key = entry.getKey();
        if (!normalizedAttribute.equals(key)) {
          builder.put(key, entry.getValue());
        }
      }
      builder.put(normalizedAttribute, normalizeParameterValue(normalizedAttribute, value));
      MediaType mediaType = new MediaType(type, subtype, builder.build());
      // Return one of the constants if the media type is a known type.
      return MoreObjects.firstNonNull(KNOWN_TYPES.get(mediaType), mediaType);
    }