public Slime decodeOrThrow(Slime slime, byte[] bytes) {
        in = new BufferedInput(bytes);
        next();
        decodeValue(slimeInserter.adjust(slime));
        if (in.failed()) {
            throw new JsonParseException(in);
        }
        return slime;
    }
Decode bytes as a UTF-8 JSON into Slime, or throw {@link JsonParseException} on invalid JSON.
vespajlib/src/main/java/com/yahoo/slime/JsonDecoder.java