public void ShiftColumnDown()
{
IGridConfiguration conf = CreateTestConfig();
IGrid grid = new SquareGrid(conf);
List <ICellContent> contents = new List <ICellContent>(conf.ColumnCount * conf.RowCount);
FillColumnContents(grid, contents);
Assert.AreSame(contents[0], grid.Columns[0][0].Content);
Assert.AreSame(contents[1], grid.Columns[0][1].Content);
ICellContent firstRowContent = grid.Columns[0][0].Content;
grid.Accept(new ColumnDownShifter(0, 3));
Assert.AreSame(firstRowContent, grid.Columns[0][3].Content);
grid.Accept(new ColumnDownShifter(0, 10));
Assert.AreSame(firstRowContent, grid.Columns[0][3].Content);
grid.Accept(new ColumnDownShifter(0, 13));
Assert.AreSame(firstRowContent, grid.Columns[0][1].Content);
}