libdbusmenu-gtk3-4 16.04.1+18.10.20180917-0ubuntu1 (amd64 binary) in ubuntu cosmic

 libdbusmenu passes a menu structure across DBus so that a program can
 create a menu simply without worrying about how it is displayed on the
 other side of the bus.
 .
 This package contains shared libraries to be used by GTK+ applications.