Learning D-Bus

https://www.freedesktop.org/wiki/Software/dbus/
https://www.freedesktop.org/wiki/IntroductionToDBus/
https://www.packtpub.com/mapt/book/application_development/9781849519427/10/ch10lvl1sec126/time-for-action–listening-to-d-bus
https://dbus.freedesktop.org/doc/dbus-specification.html
https://stackoverflow.com/questions/2830858/controlling-gnome-volume-using-dbus
https://dbus.freedesktop.org/doc/dbus-tutorial.html#concepts
https://dbus.freedesktop.org/doc/diagram.svg
https://developer.gnome.org/NetworkManager/stable/spec.html
https://developer.gnome.org/NetworkManager/stable/gdbus-org.freedesktop.NetworkManager.html
http://www.beautifulwork.org/wp-content/uploads/2018/11/dbus.pdf
http://www.beautifulwork.org/wp-content/uploads/2018/11/dbus.docx