public override ReadOnlyCollection<Move> GetValidMoves(Position from, bool returnIfAny, ChessGame game, Func<Move, bool> gameMoveValidator)
{
ChessUtilities.ThrowIfNull(from, "from");
ReadOnlyCollection<Move> horizontalVerticalMoves = new Rook(Owner).GetValidMoves(from, returnIfAny, game, gameMoveValidator);
if (returnIfAny && horizontalVerticalMoves.Count > 0)
return horizontalVerticalMoves;
ReadOnlyCollection<Move> diagonalMoves = new Bishop(Owner).GetValidMoves(from, returnIfAny, game, gameMoveValidator);
return new ReadOnlyCollection<Move>(horizontalVerticalMoves.Concat(diagonalMoves).ToList());
}