SUMMARY
A way to easily clear all notifications OR some by the use of a keyboard shortcut.
The button for removing all notifications is too hidden and doesn't seem to have a keyboard centric alternative

STEPS TO REPRODUCE
1. Receive plenty of notifications
2. Open the systemtray
3. Click button for "notifications"
4. Find the little "Sweeper" button
5. Click that
6. No Notifications

OBSERVED RESULT
Fiddly to click if you often don't use a mouse and annoying if you have a lot of notifications you don't care about in a long list

EXPECTED RESULT
A quick shortcut to "clear all" or that and one for "Clear all low priority"

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION