code: public static Instant randomInstantAfter(Instant after) {
      checkArgument(after != null, "After must be non-null");
      checkArgument(after.isBefore(MAX_INSTANT), "Cannot produce date after %s", MAX_INSTANT);
      return randomInstant(after.plus(1, MILLIS), MAX_INSTANT);
    }
docs: Returns a random {@link Instant} that is after the given {@link Instant}.
  
  @param after the value that returned {@link Instant} must be after
  @return the random {@link Instant}
  @throws IllegalArgumentException if after is null or if after is equal to or after {@link
  RandomDateUtils#MAX_INSTANT}