I was reading the source code for a GitHub project (JClouds-Chef) and stumbled across the [most peculiar looking Java](https://github.com/jclouds/jclouds-examples/blob/master/chef-basics/src/main/java/org/apache/jclouds/examples/chef/basics/MainApp.java#L292):

```
Iterable<Module> modules =
    ImmutableSet.<Module> of(new SshjSshClientModule(), new SLF4JLoggingModule(),
        new EnterpriseConfigurationModule());

```

What is `of`? How is this valid Java? Is `of` a method? If so, where is it defined? Is it some weird, obscure Java operator that is hardly ever used? Is it something weird like a lambda? I'm tearing my hair out trying to figure out where it is, what it does, and where it's defined!