private static void int2(StringBuilder buf, int i) {
    buf.append((char) ('0' + (i / 10) % 10));
    buf.append((char) ('0' + i % 10));
  }
Parses a fraction, multiplying the first character by {@code multiplier}, the second character
by {@code multiplier / 10}, the third character by {@code multiplier / 100}, and so forth.

<p>For example, {@code parseFraction("1234", 100)} yields {@code 123}.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/util/DateTimeUtils.java