The way that `plugin` and `ohai` get set in this file is confusing. Looks like the `before` blocks for the version 6 and version 7 classes are setting instance variables, then the `it_should_behave_like` blocks are defining `let` bindings for those variables, and then we call the let binding and assign the result back to the instance variable.

In terms of preferred style, I think we're gradually moving to `let` bindings for most things so I'd recommend nuking this before block and going all in on let bindings.