+bool unit_can_serialize(Unit *u);
+int unit_serialize(Unit *u, FILE *f, FDSet *fds);
+void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *value, ...) _printf_attr(4,5);
+void unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value);
+int unit_deserialize(Unit *u, FILE *f, FDSet *fds);
+