struct headline **headlines_add(struct headline **list, struct headline *h);
struct headline *headline_new(int id, const char *url, const char *title);
struct feed **feeds_add(struct feed **list, struct feed *f);
struct headline *feed_get_headline(struct feed *feed, int id);
struct headline **headlines_add(struct headline **list, struct headline *h);
struct headline *headline_new(int id, const char *url, const char *title);
struct feed **feeds_add(struct feed **list, struct feed *f);
struct headline *feed_get_headline(struct feed *feed, int id);