Using an appropriate definition of listnode, design a simple linked list class with only two member function and a defult constructor: void add(double x) boolean isMumber(double x) LinkedList(); The add function adds a new node containing x to the front (head) of the list, while the isMember function tests to see if the list contains a node with the value x. Test your linked list class by adding various numbers to the list and then testing for membership second part of the question : Modify your list class of programming challenge 1 to add a copy constructor. Test your class by making a copy of a list and then testing membership on the copy.