extern list_t *list_append(list_t *a, item_t *i);
extern list_t *list_append_list(list_t *a, list_t *b);
/* Returns an item from the list (index starts at 0), or NULL */
extern list_t *list_append(list_t *a, item_t *i);
extern list_t *list_append_list(list_t *a, list_t *b);
/* Returns an item from the list (index starts at 0), or NULL */