public void addElement_CheckElementIsAddedToBack_Int()
{
//Arrange
CustomLists <int> nums = new CustomLists <int>();
nums.Add(0);
nums.Add(1);
nums.Add(2);
int number = 3;
//Act
nums.Add(number);
//Assert
Assert.AreEqual(nums.ElementAt(nums.Count - 1), number);
}