1. Mark what is covered (Y) and what is not covered (N) in the part of the book that you were supposed to read for this week:
2a. Write a method diff that, given two integers a and b,
returns their difference a − b.
2b. Call your method in the main program for x = 1 and y = 2, and trace it step-by-step.
2c. Form a test suite for testing your method; briefly explain why you added these examples to your test suite.