One thing I'm not comfortable about: testing both cases would mean differentiating the errors in the `verify.bsh` script, so we'd be reyling on the `toString()` implementation for the `ExecutableElement`, which is not specified.

With that single test as we have here:
 * we're testing the case that's _harmful_
 * we can simply test for the presence of the error message in the log, assuming there's no other `@Provides` method that could trigger the error (which I believe is a valid assumption; if it were not, we'd have bigger problems than a false-positive test!)