The Set interface inherits its methods from Collection (java.util.Collection) and contains only those methods. In addition to sets, there are queues (java.util.Queue) and maps (java.util.Map).

Filtering collections with Guava is fairly straightforward. The following code snippet demonstrates a simple example of this. A Set of String s is provided (not shown in the code snippet, but ...

Why should you use Collections class methods rather than similarly named fields to obtain empty collections? Type safety makes the crucial difference.