/usr/share/xsessions/windowlab.desktop is in windowlab 1.40-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | [Desktop Entry]
Encoding=UTF-8
Name=WindowLab
Comment=This session logs you into WindowLab
Exec=/usr/bin/windowlab
# no icon yet, only the top three are currently used
Icon=
Type=Application
|