I liked Apache Commons collections for major versioning their releases. Collections 4 is in the collections4 package. Allows having both versions and incrementa

I liked Apache Commons collections for major versioning their releases. Collections 4 is in the collections4 package. Allows having both versions and incrementally migrating. Would have been useful because Guava is like JQuery: it had so much useful stuff, upstream stuff would often include it and then you have to worry about compatibility.