Method fromEpochMonths

base/src/main/java/net/time4j/PlainDate.java:1985–2050

(
        PlainDate context,
        long emonths,
        int dayOfMonth,
        int policy
    )

    }

    private static PlainDate fromEpochMonths(
        PlainDate context,
        long emonths,
        int dayOfMonth,
        int policy
    ) {

        if (
            (policy == OverflowUnit.POLICY_KEEPING_LAST_DATE)
            && (context.dayOfMonth == context.lengthOfMonth())
        ) {
            policy = OverflowUnit.POLICY_END_OF_MONTH;
        }

        int year =
            MathUtils.safeCast(
                MathUtils.safeAdd(
                    MathUtils.floorDivide(emonths, 12),
                    1970
                )
            );
        int month = MathUtils.floorModulo(emonths, 12) + 1;
        int max = GregorianMath.getLengthOfMonth(year, month);
        int dom = dayOfMonth;

        if (dayOfMonth > max) {
            switch (policy) {
                case OverflowUnit.POLICY_PREVIOUS_VALID_DATE:
                case OverflowUnit.POLICY_END_OF_MONTH:
                case OverflowUnit.POLICY_KEEPING_LAST_DATE:
                case OverflowUnit.POLICY_JODA_METRIC:
                    dom = max;
                    break;
                case OverflowUnit.POLICY_NEXT_VALID_DATE:
                    return PlainDate.fromEpochMonths(
                        context,
                        MathUtils.safeAdd(emonths, 1),
                        1,
                        policy);
                case OverflowUnit.POLICY_CARRY_OVER:
                    return PlainDate.fromEpochMonths(
                        context,
                        MathUtils.safeAdd(emonths, 1),
                        dayOfMonth - max,
                        policy);
                case OverflowUnit.POLICY_UNLESS_INVALID:
                    StringBuilder sb = new StringBuilder(32);
                    sb.append("Day of month out of range: ");
                    formatYear(sb, year);
                    format2Digits(sb, month);
                    format2Digits(sb, dayOfMonth);
                    throw new ChronoException(sb.toString());
                default:
                    throw new UnsupportedOperationException(
                        "Overflow policy not implemented: " + policy);
            }
        } else if(
            (dayOfMonth < max)