Method readDuration

base/src/main/java/net/time4j/SPX.java:527–549

(
        ObjectInput in,
        byte header
    )

    }

    private Object readDuration(
        ObjectInput in,
        byte header
    ) throws IOException, ClassNotFoundException {

        boolean useLong = ((header & 0xF) == 1);
        int size = in.readInt();

        if (size == 0) {
            return Duration.ofZero();
        }

        List<TimeSpan.Item<IsoUnit>> items = new ArrayList<>(size);

        for (int i = 0; i < size; i++) {
            long amount = (useLong ? in.readLong() : in.readInt());
            IsoUnit unit = (IsoUnit) in.readObject();
            items.add(TimeSpan.Item.of(amount, unit));
        }

        boolean negative = in.readBoolean();
        return new Duration<>(items, negative);
    }

    private void writeDayPeriod(ObjectOutput out)
        throws IOException {