private void outputDebateTurnSubjects(File debateTurnSubjFile,
            ArrayList<GTDebate> selectedDebates) throws Exception {
        if (verbose) {
            System.out.println("Outputing debate turn subject to " + debateTurnSubjFile);
        }
        BufferedWriter writer = IOUtils.getBufferedWriter(debateTurnSubjFile);
        for (GTDebate debate : selectedDebates) {
            for (int ii = 0; ii < debate.getNumTurns(); ii++) {
                GTTurn turn = debate.getTurn(ii);
                writer.write(turn.getId());

                GTBill bill = this.bills.get(turn.getMainBillMentioned());
                if (bill == null) {
                    writer.write("\n");
                    continue;
                }

                ArrayList<String> subjects = bill.getSubjects();
                if (subjects == null || subjects.isEmpty()) {
                    writer.write("\n");
                    continue;
                }

                for (String subject : subjects) {
                    writer.write("\t" + subject);
                }
                writer.write("\n");
            }
        }
        writer.close();
    }