public static String toString(byte c0, byte c1) {
        if (c0 >= X2.START && c0 <= X2.END && c1 >= X2.START && c1 <= X2.END) {
            int value = (c0 - X2.START) * X2.SIZE2 + (c1 - X2.START);
            return X2.chars2[value];
        }
        return new String(new byte[]{c0, c1}, 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