int unit_add_name(Unit *u, const char *name);
int unit_add_dependency(Unit *u, UnitDependency d, Unit *other);
int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name);
int unit_add_name(Unit *u, const char *name);
int unit_add_dependency(Unit *u, UnitDependency d, Unit *other);
int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name);