cairo-dock-dbus-plug-in-interf software package provides library of D-Bus interface for mono of Cairo-dock, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install cairo-dock-dbus-plug-in-interf
cairo-dock-dbus-plug-in-interf is installed in your system.
Make ensure the cairo-dock-dbus-plug-in-interf package were installed using the commands given below,
$ sudo dpkg-query -l | grep cairo-dock-dbus-plug-in-interf*
You will get with cairo-dock-dbus-plug-in-interf package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | X Window System software |
| Package | cairo-dock-dbus-plug-in-interf |
| Version | 3.4.1-1 |
| Description | library of D-Bus interface for mono of Cairo-dock |
| Sub Section | x11 |