public Duration plus(long amountToAdd, TemporalUnit unit) {
Objects.requireNonNull(unit, "unit");
if (unit == DAYS) {
return plus(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY), 0);
}
if (unit.isDurationEstimated()) {
throw new UnsupportedTemporalTypeException("Unit must not have an estimated duration");
}
if (amountToAdd == 0) {
return this;
}
if (unit instanceof ChronoUnit) {
switch ((ChronoUnit) unit) {
case NANOS:
return plusNanos(amountToAdd);
case MICROS:
return plusSeconds((amountToAdd / (1000_000L * 1000)) * 1000)
.plusNanos((amountToAdd % (1000_000L * 1000)) * 1000);
case MILLIS:
return plusMillis(amountToAdd);
case SECONDS:
return plusSeconds(amountToAdd);
}
return plusSeconds(Math.multiplyExact(unit.getDuration().seconds, amountToAdd));
}
Duration duration = unit.getDuration().multipliedBy(amountToAdd);
return plusSeconds(duration.getSeconds()).plusNanos(duration.getNano());
}
public Duration minus(Duration duration) {
long secsToSubtract = duration.getSeconds();
int nanosToSubtract = duration.getNano();
if (secsToSubtract == Long.MIN_VALUE) {
return plus(Long.MAX_VALUE, -nanosToSubtract).plus(1, 0);
}
return plus(-secsToSubtract, -nanosToSubtract);
}
public Duration plus(Duration duration) {
return plus(duration.getSeconds(), duration.getNano());
}