public static String readTombstones(Mailbox mbox, long lastSync) throws ServiceException {
public static List<Integer> readTombstones(Mailbox mbox, long lastSync) throws ServiceException {
    public static String readTombstones(Mailbox mbox, long lastSync) throws ServiceException {        Connection conn = mbox.getOperationConnection();        StringBuilder result = new StringBuilder();        PreparedStatement stmt = null;        ResultSet rs = null;        try {            stmt = conn.prepareStatement("SELECT ids FROM " + getTombstoneTableName(mbox.getId()) +                    " WHERE sequence > ? AND ids IS NOT NULL ORDER BY sequence");            stmt.setLong(1, lastSync);            rs = stmt.executeQuery();            while (rs.next())                result.append(result.length() == 0 ? "" : ",").append(rs.getString(1));            return result.toString();        } catch (SQLException e) {            throw ServiceException.FAILURE("reading tombstones since change: " + lastSync, e);        } finally {            DbPool.closeResults(rs);            DbPool.closeStatement(stmt);        }    }