[JAVA8] truncate java 8 LocalDateTime

LocalDateTime now =  LocalDateTime.now();
LocalDateTime roundFloor =  now.truncatedTo(ChronoUnit.MINUTES);
LocalDateTime roundCeiling =  now.truncatedTo(ChronoUnit.MINUTES).plusMinutes(1);

http://stackoverflow.com/questions/25552023/round-minutes-to-ceiling-using-java-8