-int bus_unit_method_start_generic(sd_bus *bus, sd_bus_message *message, Unit *u, JobType job_type, bool reload_if_possible);
-int bus_unit_method_kill(sd_bus *bus, sd_bus_message *message, void *userdata);
-int bus_unit_method_reset_failed(sd_bus *bus, sd_bus_message *message, void *userdata);
+int bus_unit_method_start_generic(sd_bus *bus, sd_bus_message *message, Unit *u, JobType job_type, bool reload_if_possible, sd_bus_error *error);
+int bus_unit_method_kill(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error);
+int bus_unit_method_reset_failed(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error);