+ * where to actually set the state and call unit_notify().
+ *
+ * This must not reference other units (maybe implicitly through spawning
+ * jobs), because it is possible that they are not yet coldplugged.
+ * Such actions must be deferred until the end of coldplug bу adding
+ * a "Unit* -> int(*)(Unit*)" entry into the hashmap.
+ */
+ int (*coldplug)(Unit *u, Hashmap *deferred_work);