DurationFormatter

[lars-sh]

        // TODO: Build something similar to the DateTimeFormatter
        private static String formatDuration(final Duration duration) {
            final StringBuilder builder = new StringBuilder();
            if (duration.isNegative()) {
                builder.append('-');
            }
            builder.append(duration.toDays()).append(' ');
            builder.append(duration.toHours()).append(':');
            builder.append(duration.toMinutes()).append(':');
            builder.append(duration.toSeconds());
            builder.append('.').append(duration.toMillis());
            builder.append('#').append(duration.toNanos());
            return builder.toString();
        }