public void ToRelativeCoordinatesConversionTest()
        {
            var pos    = new CellPosition(3, 6);
            var origin = new CellPosition(2, 2);

            var relativePos = pos.ToRelativeCoordinates(origin);

            relativePos.RowIndex.Should().Be(2);
            relativePos.ColumnIndex.Should().Be(5);
        }