code: public static LocalDateTime randomLocalDateTimeAfter(LocalDateTime after) {
      checkArgument(after != null, "After must be non-null");
      Instant instant = randomInstantAfter(after.toInstant(UTC_OFFSET));
      return LocalDateTime.ofInstant(instant, UTC);
    }
docs: Returns a random {@link LocalDateTime} that is after the given {@link LocalDateTime}.
  
  @param after the value that returned {@link LocalDateTime} must be after
  @return the random {@link LocalDateTime}
  @throws IllegalArgumentException if after is null or if after is equal to or after {@link
  RandomDateUtils#MAX_INSTANT}