1typedef struct node {
 2  struct node *next;
 3  void *data;
 4} Node;
 5
 6typedef void (*Printer)(void *);
 7
 8Node *list_initialize(void *data);
 9Node *list_get(Node *from, int index);
10Node *list_add(Node *head, void *data);
11void list_inspect(Node *self, Printer printer);