public void TestRecursiveMultiply(int val1, int val2, int expected)
 {
     Assert.Equal(expected, RecursiveMath.RecursiveMultiply(val1, val2));
 }
 public void TestRecursiveMultiply()
 {
     Assert.Equal(20, RecursiveMath.RecursiveMultiply(4, 5));
     Assert.Equal(-10, RecursiveMath.RecursiveMultiply(2, -5));
     Assert.Equal(0, RecursiveMath.RecursiveMultiply(10, 0));
 }