/usr/share/doc/graphviz/pdf/gv2gml.1.pdf is in graphviz-doc 2.36.0-0ubuntu3.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/graphviz/pdf/gml2gv.1.pdf
/usr/share/doc/graphviz/pdf/gml2gv.1.pdf