public void AddLeftNegRightPos()
 {
     Assert.AreEqual(9, BitOp.Add(-3, 12));
 }
 public void AddTwoNegatives()
 {
     Assert.AreEqual(-16, BitOp.Add(-9, -7));
 }
 public void AddTwoPositivies()
 {
     Assert.AreEqual(14, BitOp.Add(2, 12));
 }
 public void AddRightPosLeftNeg()
 {
     Assert.AreEqual(-4, BitOp.Add(4, -8));
 }