if (vnaFrameAfter.getLoad(v) == null) i.remove();
if (vnaFrameAfter.getLoad(v) == null) { if (IsNullValueAnalysis.DEBUG) System.out.println("PURGING " + v); i.remove(); }
	public void cleanStaleKnowledge(ValueNumberFrame vnaFrameAfter) {		for(Iterator<ValueNumber> i = knownValueMap.keySet().iterator(); i.hasNext(); ) {			ValueNumber v = i.next();			if (vnaFrameAfter.getLoad(v) == null) i.remove();		}			}