Seeing that there already is something called `call_with_output` we might actually want to refactor this so far as to be able to call things like the following:
````ruby
call 'killall ruby'
call_with_output 'killall ruby'
call_zypper 'refs'
call_zypper_with_output 'refs'
````
Of course, any solution that uses additional arguments might make our code even cleaner:
````ruby
call :zypper, :with_output, 'refs'
call :system, :silently, 'killall ruby'
````
Anything is fine. Minimizing the string duplication, however, might make the code a lot more maintainable. Changes like adding the `--root` parameter only need to be added in once place instead of many.