@FlowBreeze thanks for the PR :) you need to install dbus-send in circleci OR mock it in order to get the tests to pass.

Let me know if you need a hand with this. Happy to help

@MichaelAquilina I'm Sorry, I never use circleci before so I just rewrite my code and add dbus-send check.
If you need to configure circleci, you may do it by yourself.

@MichaelAquilina
yes in here is unclear, so i change it to 'unknown'

here is my consideration:
dbus-send is a freedesktop buildin tool,
So I think it is rarely occurred an system has notify-send but not dbus-send until i met an error from circle ci

• if system has dus-send and doesn't hava a 'org.freedesktop.Notifications' consumer,then disable notify
• if system has notify-send but not dus-send,then enable notify service to keep the backward capability (and pass circleci check), although i think it's rarely happens

And It's ok to change my code as you like