kwin-wayland-backend-virtual 4:5.12.5-0ubuntu0.1 (amd64 binary) in ubuntu bionic

 KWin (pronounced as one syllable "kwin") is the window
 manager for the KDE Plasma Desktop. It gives you complete
 control over your windows, making sure they're not in the way
 but aid you in your task. It paints the window decoration,
 the bar on top of every window with (configurable) buttons
 like close, maximize and minimize. It also handles placing
 of windows and switching between them.
 .
 This backend allows running kwin-wayland in headless mode, useful for testing,
 or in the Cloud.