code: @Override
  	public Object getValueAt(int row, int col) {
  		// Get the href and the required field
  		HistoryReference href = hrefList.get(row);
  		try {
  			switch (this.columns[col]) {
  			case HREF_ID:		return href.getHistoryId();
  			case TYPE_FLAG:		return this.getHrefTypeIcon(href);
  			case METHOD:		return href.getMethod();
  			case URL:			return href.getURI().toString();
  			case CODE:			return href.getStatusCode();
  			case REASON:		return href.getReason();
  			case RTT:			return href.getRtt();
  			case SIZE:			return href.getResponseBodyLength();
  			case SESSION_ID:	return href.getSessionId();
  			case ALERT_FLAG:	return this.getHrefAlertIcon(href);
  			case TAGS:			return listToCsv(href.getTags());
  			default:			return null;
  			}
  		} catch (Exception e) {
  			logger.error(e.getMessage(), e);
  			return null;
  		}
  	}
docs: This should be overriden for any custom columns