public Piece getPiece(String pos) {
Position p = new Position(pos);
return chessBoard.get(p.getPostionRow()).getPiece(p.getPostionCol());
}
public void addPiece(String pos, Piece piece) {
Position p = new Position(pos);
positionList.add(p);
chessBoard.get(p.getPostionRow()).addPiece(p.getPostionCol(), piece);
}