code: public void resetSort() {
          final ValueExpression origSortBy = (ValueExpression) getStateHelper().get(PropertyKeys.origSortBy);
          // Set sort by even if null to restore to initial sort order.
          setSortByValueExpression(origSortBy);
  
          final String origSortOrder = (String) getStateHelper().get(PropertyKeys.origSortOrder);
          if (origSortOrder != null) {
              setSortOrder(origSortOrder);
          }
      }
docs: Resets the sorting to the originally specified values (if any)