3. You are given two dummy-headed singly linked lists, and write a method to sum the integers represented in two different lists. The input lists will have single digits in each node. The digits in each node concat to form an integer. List 1 x List 2 x Sample Input 4-5-3 9-5-2 Sample Output x→ 1-4-0-5 Explanation: List 1 represents the integer 453. List 2 represents the integer 952. 453+952-1405. Hence, List 3 contains 1 →40→5.

Explain what is meant by "testability," and give a quick rundown of the compiler.

Using the language of the class, describe a real life object that would be a useful or interesting class in python. Describe what variables it would save, what functions it would have, and either what it would be useful or why you think it would be interesting.   In class we created a Dog, Student, and Seat class, and you can use those python files as the basis of your class.

Can we obtain a rundown of the compiler and an explanation of the value of testability?