replace Optional with java.util.Optional
- replace Optional.fromNull() with Optional.ofNull()
- replace Optional.absent() with Optional.empty()
- replace Optional.transform() with Optional.map()
- replace Optional.or() with Optional.orElse()
replace FluentIterable with Stream
upgrade Lombok project to the latest version
1.12.6 didn't work with Eclipse Luna in my case, and 1.14.2 was OK.