Which component empties the trash?

[Markus]

Hi.
When emptying the Trash takes a bit longer, an empty notification is 
displayed.
A while ago I filed a bug about it. 
<https://bugs.kde.org/show_bug.cgi?id=209454>

At first I thought it's a Plasma bug. Then I thought it's a Dolphin bug.
But neither team seems responsible (at least I got no response).
So I guess something/someone else is responsible, but I have no idea which.
Could anybody of you please point me into the right direction?

Thanks,
Markus