18. Implement the following specification for a client Boolean function that returns true if two stacks are identical and false otherwise. Boolean Identical(StackType stack1, StackType stack2) Function: Determines if two stacks are identical. Preconditions: stack1 and stack2 have been initialized. Postconditions: stack1 and stack2 are unchanged. A WAZ Function value = (stack1 and stack2 are identical)