How do I test this kind of method? (I'm new to java) [closed]

I have been assigned to test some methods of a game implementation, such as the one presented. I'm new to java and I don't really know how to test this kind of method.

 private void play() {
         turns = 0;
        update();
        while (!gameOver()) {
            while (current <= nrPlayers) {
                players[current].makeMove(board);
                incTurns(); //increments turns
                current++;
                update();
            }
            current = 0;


        }
        printOutcome();
    }