Method multipliedBy

base/src/main/java/net/time4j/Duration.java:1688–1719

(int factor)

     * @throws  ArithmeticException in case of long overflow
     */
    public Duration<U> multipliedBy(int factor) {

        if (
            this.isEmpty()
            || (factor == 1)
        ) {
            return this;
        } else if (factor == 0) {
            return ofZero();
        } else if (factor == -1) {
            return new Duration<>(this, true);
        }

        List<Item<U>> newItems = new ArrayList<>(this.count());
        int scalar = Math.abs(factor);

        for (int i = 0, n = this.count(); i < n; i++) {
            Item<U> item = this.getTotalLength().get(i);
            newItems.add(
                Item.of(
                    MathUtils.safeMultiply(item.getAmount(), scalar),
                    item.getUnit()
                )
            );
        }

        return new Duration<>(
            newItems,
            ((factor < 0) != this.isNegative())
        );

    }

    /**
     * <p>Creates a duration as union of this instance and given timespan