Restart Plasma during package installation/upgrade

[Rob Hasselbaum]

Is there any way to restart Plasma as part of a package installation
or upgrade? I have a data engine that interacts with a D-Bus system
bus service, which gets installed at the same time. Unfortunately, the
data engine and applet don't start correctly when they're first
installed. It seems the data engine can't activate or communicate with
the D-Bus service until I restart Plasma, which seems to give it
enough of a kick that things work fine after that. (Not sure why
restarting Plasma should affect D-Bus in this way, but it does.)
Anyway, I'd like to automate this as part of the package installation
or find some other solution that doesn't require user intervention.
Any pointers would be much appreciated. Thanks!