public void TestSum()
{
int[] arr1 = new int[0];
int rs1 = Program2.Sum(arr1);
Assert.AreEqual(0, rs1);
int[] arr2 = new int[] { 1, 2, 3, 4, -1, 5 };
int rs2 = Program2.Sum(arr2);
Assert.AreEqual(14, rs2);
}