public static boolean isInt32(BigInteger value) {
        if (FIELD_BIGINTEGER_MAG_OFFSET != -1) {
            int[] mag = (int[]) UNSAFE.getObject(value, FIELD_BIGINTEGER_MAG_OFFSET);
            return mag.length == 0
                    || (mag.length == 1 && (mag[0] >= 0 || (mag[0] == Integer.MIN_VALUE && value.signum() == -1)));
        }

        return value.compareTo(BIGINT_INT32_MIN) >= 0 && value.compareTo(BIGINT_INT32_MAX) <= 0;
    }
All the positive powers of 10 that can be
represented exactly in double/float.
core/src/main/java/com/alibaba/fastjson2/util/TypeUtils.java