closest equivalent to KApplicationPrivate::init() ?

[René J.V. Bertin]

Morning!

Is there anything like a closest equivalent to KApplicationPrivate::init() in KF5 Frameworks?
I added a "bring application to the foreground" call (to a KWindowSystem helper function) in there, which alleviated the issue of applications remaining somewhere in the background on OS X. 
I'm still keeping an eye out for central locations where I could call that helper function.

Thanks,
René