internal BoardBox(SudokuBoard board, int box)
{
_board = board;
_box = box;
}
internal BoardRow(SudokuBoard board, int row)
{
_board = board;
_row = row;
}
internal BoardCol(SudokuBoard board, int col)
{
_board = board;
_col = col;
}
private void OnBoardChanged(SudokuBoard sender)
{
IsValid = BoardValidation.Validate(Board);
}