javac 2DTicTacToe.java 
2DTicTacToe.java:14: <identifier> expected
public class 2DTicTacToe implements AnyTicTacToe
            ^
2DTicTacToe.java:20: illegal start of type
    public 2DTicTacToe()
           ^
2DTicTacToe.java:20: invalid method declaration; return type required
    public 2DTicTacToe()
             ^
3 errors