public void RemoveLastTest()
{
int count = _array.Count;
_array.RemoveLast();
Assert.Equal(count - 1, _array.Count);
Assert.Equal(0, _array[_array.Count - 1]);
_array.RemoveLast();
Assert.Equal(count - 2, _array.Count);
Assert.Equal(40, _array[_array.Count - 1]);
}