Method category index
instance creation (class)
Create an instance with the given next link
Answer the next item in the list
Set the next item in the list
Retrieve a node (instance of Link) that is at a distance of `index' after the receiver.
at: index put: object
This method should not be called for instances of this class.
Evaluate aBlock for each element in the list
Answer the number of elements in the list. Warning: this is O(n)