public void InequalityWorks()
        {
            var cellRefA1         = new CellRef("A1");
            var cellRefA2FromInts = new CellRef(1, 2);

            (cellRefA1 != cellRefA2FromInts).Should().BeTrue();
            (cellRefA1 == cellRefA2FromInts).Should().BeFalse();
            cellRefA1.Equals(cellRefA2FromInts).Should().BeFalse();
        }