+int sd_bus_error_setf(sd_bus_error *e, const char *name, const char *format, ...) _sd_printf_attr_(3, 0);
+int sd_bus_error_set_const(sd_bus_error *e, const char *name, const char *message);
+int sd_bus_error_set_errno(sd_bus_error *e, int error);
+int sd_bus_error_set_errnof(sd_bus_error *e, int error, const char *format, ...) _sd_printf_attr_(3, 0);
+int sd_bus_error_get_errno(const sd_bus_error *e);