/usr/lib/x86_64-linux-gnu/libpolkit-gtk-mate-1.so is in libmatepolkit-dev 1.6.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libpolkit-gtk-mate-1.so.0.0.0
/usr/lib/x86_64-linux-gnu/libpolkit-gtk-mate-1.so.0.0.0