int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error);
int link_send_changed(Link *link, const char *property, ...) _sentinel_;
int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error);
int link_send_changed(Link *link, const char *property, ...) _sentinel_;