if (IsNullValueAnalysisFeatures.TRACK_KNOWN_VALUES) {
if (trackValueNumbers) {
	protected void mergeInto(IsNullValueFrame other, IsNullValueFrame result) throws DataflowAnalysisException {		super.mergeInto(other, result);		if (IsNullValueAnalysisFeatures.TRACK_KNOWN_VALUES) {			result.mergeKnownValuesWith(other);		}			}