public static String toString(byte ch) {
        if (ch >= 0 && ch < X2.chars.length) {
            return X2.chars[ch];
        }
        return new String(new byte[]{ch}, StandardCharsets.ISO_8859_1);
    }
All the positive powers of 10 that can be
represented exactly in double/float.
core/src/main/java/com/alibaba/fastjson2/util/TypeUtils.java