/usr/ is in libflowcanvas-dev 0.7.1+dfsg0-0.2ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/libflowcanvas.so
/usr/include/flowcanvas/Canvas.hpp
/usr/lib/
/usr/lib/pkgconfig/
/usr/lib/pkgconfig/flowcanvas.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/libflowcanvas-dev/
/usr/share/doc/libflowcanvas-dev/copyright
/usr/include/
/usr/include/flowcanvas/
/usr/include/flowcanvas/Port.hpp
/usr/include/flowcanvas/Connectable.hpp
/usr/include/flowcanvas/Ellipse.hpp
/usr/include/flowcanvas/Module.hpp
/usr/include/flowcanvas/types.hpp
/usr/include/flowcanvas/Item.hpp
/usr/include/flowcanvas/flowcanvas.hpp
/usr/include/flowcanvas/Connection.hpp
/usr/share/doc/libflowcanvas-dev/changelog.Debian.gz