Help on a minimum example of sending key and getting the preedit and candidate list through fcitx dbus interface

Similar to this project, I am trying to make an emacs client using fcitx dbus interface. I need a minimal example of getting the preedit and candidate list through fcitx dbus interface. 
Please kindly have a look at my issue here https://github.com/QiangF/emacs-dbus-proxy/issues/1 
