@Override
    public void reset() {
        openSingleSelects.clear();
        openLabels.clear();
        openMediaElements.clear();
        openActiveDescendants.clear();
        ariaOwnsIdsByRole.clear();
        needsAriaOwner.clear();
        formControlReferences.clear();
        formElementReferences.clear();
        formControlIds.clear();
        formElementIds.clear();
        listReferences.clear();
        listIds.clear();
        ariaReferences.clear();
        allIds.clear();
        siblingSources.clear();
        secondLevelH1s.clear();
        sectioningElementPtrs.clear();
    }
@see nu.validator.checker.Checker#startDocument()
src/nu/validator/checker/schematronequiv/Assertions.java