Dene and implement all appropriate contracts using the adbc tool (and design by contract), such as @invariant for invariant, @requires for preconditions, @ensures for postconditions.

5

3 Defining class Node A Node has two parts: 1. data holds the element, of some generic type E, stored in the current node, and 2. next holds a reference to the next node in the list. The interface of Node is defined as follows: public Node (E data) Constructor. precondition: The specified data is not null. postcondition: None. public void setData (E data) Sets the value of the data element. precondition: The specified data is not null. postcondition: None. public E getDataC) Returns the value of data element. precondition: None. postcondition: None. public void setNext (Node next) Sets the next node. precondition: The specified node is not null. postcondition: The specified node is currently accessible through next. public Node getNext() Obtains the next node. precondition: None postcondition: None