Since this is a fairly involved method, it might be good to include an example for this, like so:

```ruby
# @example Set the default Ruby to be 1.9
#   run_action_on_module('eselect', 'ruby', :set, 'ruby19')
#   #=> "the_parsed_output"
```

The syntax for YARD `@example` blocks is at http://rubydoc.info/gems/yard/file/docs/Tags.md#example