Method illegalEnPassant

src/main/java/game/Board.java:262–283

(final Move move, final Piece king)

    }

    private boolean illegalEnPassant(final Move move, final Piece king) {
        if (move.piece.sameType(PieceType.PAWN) && move.captureMove && move.captureCell != move.target) {
            //does not expose an attack on the king.
            //The king is not discovered with the capture
            //ignore the captured and capturing pawn, and then check if the ray is a check.
            final Set<Piece> ignorePawns = new HashSet<>();
            ignorePawns.add(move.piece);
            ignorePawns.add(getPiece(move.captureCell.row, move.captureCell.col));
            final Line line = new Line(move.captureCell, king.position);
            if (line.isStraight) {
                for (int row = king.position.row + line.rowDiff, col = king.position.col + line.colDiff; Utils.withinBoardLimits(row, col); row = row + line.rowDiff, col = col + line.colDiff) {
                    if (!isEmpty(row, col) && !ignorePawns.contains(getPiece(row, col))) {
                        final Piece piece = getPiece(row, col);
                        return piece.color != king.color && (piece.sameType(line.minorPieceType) || piece.sameType(PieceType.QUEEN));
                    } else if (move.target.equals(Cell.get(row, col))) {
                        break;
                    }
                }
            }
        }
        return false;
    }

    private Set<Cell> rayOfCheck(Piece king, Piece attacker) {
        final Set<Cell> stopCheck = new HashSet<>();