### Relevant articles:
- [New Stream, Comparator and Collector in Guava 21](http://www.baeldung.com/guava-21-new)
- [New in Guava 21 common.util.concurrent](http://www.baeldung.com/guava-21-util-concurrent)
- [Zipping Collections in Java](http://www.baeldung.com/java-collections-zip)