public static String toString(byte[] utf8) {
        // This is just wrapper for String::new. Pre-Java 9 this had a more efficient approach for ASCII-onlu strings.
        return new String(utf8, UTF_8);
    }
Decode a UTF-8 string.

@param utf8 the bytes to decode
@return Utf8 encoded array
vespajlib/src/main/java/com/yahoo/text/Utf8.java