int manager_start_unit(Manager *manager, const char *unit, DBusError *error, char **job);
int manager_stop_unit(Manager *manager, const char *unit, DBusError *error, char **job);
int manager_kill_unit(Manager *manager, const char *unit, KillWho who, int signo, DBusError *error);
int manager_start_unit(Manager *manager, const char *unit, DBusError *error, char **job);
int manager_stop_unit(Manager *manager, const char *unit, DBusError *error, char **job);
int manager_kill_unit(Manager *manager, const char *unit, KillWho who, int signo, DBusError *error);