code: private String getFilterValues(final TableDataModel dataModel, final int rowIndex) {
  		List<String> filterValues = dataModel.getFilterValues(rowIndex);
  
  		if (filterValues == null || filterValues.isEmpty()) {
  			return null;
  		}
  
  		StringBuffer buf = new StringBuffer(filterValues.get(0));
  
  		for (int i = 1; i < filterValues.size(); i++) {
  			buf.append(", ");
  			buf.append(filterValues.get(i));
  		}
  
  		return buf.toString();
  	}
docs: Retrieves the filter values for the given row in the data model, as a comma-separated string.
  
  @param dataModel the data model.
  @param rowIndex the row index.
  @return the filter values string.