code: public static Interval of(Instant startInclusive, Duration duration) {
          Objects.requireNonNull(startInclusive, "startInclusive");
          Objects.requireNonNull(duration, "duration");
          if (duration.isNegative()) {
              throw new DateTimeException("Duration must not be negative");
          }
          return new Interval(startInclusive, startInclusive.plus(duration));
      }
docs: Obtains an instance of {@code Interval} from the start and a duration.
  <p>
  The end instant is calculated as the start plus the duration.
  The duration must not be negative.
  
  @param startInclusive  the start instant, inclusive, not null
  @param duration  the duration from the start to the end, not null
  @return the interval, not null
  @throws DateTimeException if the end is before the start,
  or if the duration addition cannot be made
  @throws ArithmeticException if numeric overflow occurs when adding the duration