Given a class diagram for List as in Figure 1. Complete a linked list program given in Program 1. Define List class and write the implementation for all the function members for List to accomplish each of the following tasks: List -head: ItemNode* - tail: Item Node* + task1(Item Node*): void + task2(Item Node*): void + task3(): void + task4(Item Node*, int): void + task5(int): void + task6(): void Figure 1: List class 1 2 3 4 5 6 7 //Program 1 class ItemNode { public: string name; float price; ItemNode *aft, *bef; ItemNode (string n=NULL, float p=0) { name = n; price = p; aft = NULL; bef = NULL; } }; 8 9 10 11 12 13 14 15 16 17 18 int main() { List ItemList; ItemNode *n1 = new ItemNode ("Book", 9.59); ItemNode *n2 = new ItemNode ("Ruler", 3.45); ItemNode *n3 = new ItemNode ("Pen", 5.69); ItemNode *n4 = new ItemNode ("Eraser", 2.25); 19 20 21 22 23 24 25 26 27 cout fixed