There are tons of commons libraries out there so, why another one?
RESTscape java subprojects need one utilities library for common and shared methods. Developers often don't know that there's already a library with a similar method (or, may be, there's no such library). This project will host all that common behaviour until the same or other developer point out a stronger library that could be used instead, and then the method will get deprecated.
Now, just have a look at the API.