code: protected void decodeFilters(final FacesContext context, final Sheet sheet, final Map<String, String> params,
                  final String clientId) {
          int renderCol = 0;
          for (final SheetColumn column : sheet.getColumns()) {
              if (!column.isRendered()) {
                  continue;
              }
  
              if (column.getValueExpression("filterBy") != null) {
                  final String value = params.get(clientId + "_filter_" + renderCol);
                  column.setFilterValue(value);
              }
  
              renderCol++;
          }
      }
docs: Decodes the filter values
  
  @param context
  @param sheet
  @param params
  @param clientId