if (IsNullValueAnalysisFeatures.TRACK_KNOWN_VALUES) {
if (trackValueNumbers) {
	private boolean checkForKnownValue(Instruction obj) {		if (IsNullValueAnalysisFeatures.TRACK_KNOWN_VALUES) {			try {				// See if the value number loaded here is a known value				ValueNumberFrame vnaFrameAfter = vnaDataflow.getFactAfterLocation(getLocation());				if (vnaFrameAfter.isValid()) {					ValueNumber tosVN = vnaFrameAfter.getTopValue();					IsNullValue knownValue = getFrame().getKnownValue(tosVN);					if (knownValue != null) {						//System.out.println("Produce known value!");						// The value produced by this instruction is known.						// Push the known value.						modelNormalInstruction(obj, getNumWordsConsumed(obj), 0);						produce(knownValue);						return true;					}				}			} catch (DataflowAnalysisException e) {				// Ignore...			}		}			return false;	}