Method heuristic

src/main/java/game/Board.java:689–692

()

    }

    private int heuristic() {
        return playerPieces.get(playerToMove).stream().mapToInt(piece -> approxValue.get(piece.pieceType)).sum()
                - playerPieces.get(Color.opponent(playerToMove)).stream().mapToInt(piece -> approxValue.get(piece.pieceType)).sum();
    }

    public boolean isDraw() {
        if (isThreeFoldRepetition || fiftyMoveDraw) {