code: public static Year randomYearBefore(Year before) {
      checkArgument(before != null, "Before must be non-null");
      return randomYearBefore(before.getValue());
    }
docs: Returns a random {@link Year} that is before the given {@link Year}.
  
  @param before the value that returned {@link Year} must be before
  @return the random {@link Year}
  @throws IllegalArgumentException if before is null or if before is less than or equal to {@link
  RandomDateUtils#MIN_INSTANT}