public Duration get() {
        return Duration.between(
                startTime,
                Objects.requireNonNullElseGet(endTime, Instant::now));
    }
@return The duration between the start and stop time (if {@link DurationTimer#stop()} was called)
else the duration between the start time and now.
stroom-util/src/main/java/stroom/util/logging/DurationTimer.java