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