+/*
+ * irc_radixtree_foreach_start_from() begins an iteration over all items,
+ * starting with the item specified by `key`. If there is only one iteration
+ * in progress at a time, it is permitted to remove the current element
+ * of the iteration (but not any other element).
+ * Use NULL as a key to have it start at the beginning.
+ */
+extern void irc_radixtree_foreach_start_from(struct irc_radixtree *dtree, struct irc_radixtree_iteration_state *state, const char *key);
+