A Reference-Based Implementation of the ADT Stack . A reference-based implementation Required when the stack needs to grow and shrink dynamicaly StackReferenceBased Implements StackInterface top is a reference to the head of a linked list of items A Reference-Based Implementation of the ADT Stack Figure 7-6 A relerence-based A Reference-Based Implementation of the ADT Stack public class StackReferenceBased implements StackInterface private Node top: public StackReferenceBased) top nult end default constructor public boolean isEmpty) return top-null; } end isEmpty