private static SerializationFormat register(
            BiMap<String, SerializationFormat> uriTextToFormats,
            Multimap<MediaType, SerializationFormat> simplifiedMediaTypeToFormats,
            SerializationFormatProvider.Entry entry) {

        checkState(!uriTextToFormats.containsKey(entry.uriText),
                   "serialization format registered already: %s", entry.uriText);

        final SerializationFormat value = new SerializationFormat(
                entry.uriText, entry.primaryMediaType, entry.mediaTypes);
        for (MediaType type : entry.mediaTypes) {
            checkMediaType(simplifiedMediaTypeToFormats, type);
        }

        uriTextToFormats.put(entry.uriText, value);
        for (MediaType type : entry.mediaTypes) {
            simplifiedMediaTypeToFormats.put(type.withoutParameters(), value);
        }

        return value;
    }
Unknown serialization format. Used when some serialization format is desired but the server
failed to understand or recognize it.
core/src/main/java/com/linecorp/armeria/common/SerializationFormat.java