typedef struct _List {
	/* first node in list */
	ListNode * firstNode;
	/* last node in list */
	ListNode * lastNode;
	/* function used to free data stored in nodes of the list */
	ListFreeDataFunc * freeDataFunc;
	/* number of nodes */
	long numberOfNodes;
	/* array for searching when list is sorted */
	ListNode ** nodesArray;
	/* sorted */
	int sorted;
	/* weather to strdup() key's on insertion */
	int strdupKeys;
} List;