if (derefParamSet.isEmpty()) {
if (derefParamSet == null || derefParamSet.isEmpty()) {
	private void checkUnconditionalDerefDatabase(			Location location,			ValueNumberFrame vnaFrame,			UnconditionalValueDerefSet fact) throws DataflowAnalysisException {				ParameterNullnessPropertyDatabase database =			AnalysisContext.currentAnalysisContext().getUnconditionalDerefParamDatabase();		if (database == null) {			return;		}				InvokeInstruction inv = (InvokeInstruction) location.getHandle().getInstruction();		TypeFrame typeFrame = typeDataflow.getFactAtLocation(location);		if (!typeFrame.isValid()) {			return;		}				SignatureParser sigParser = new SignatureParser(inv.getSignature(methodGen.getConstantPool()));		int numParams = sigParser.getNumParameters();				try {			Set<JavaClassAndMethod> targetSet = Hierarchy.resolveMethodCallTargets(					inv,					typeFrame,					methodGen.getConstantPool());						// Compute the intersection of all properties			ParameterNullnessProperty derefParamSet = new ParameterNullnessProperty();			for (JavaClassAndMethod target : targetSet) {				ParameterNullnessProperty targetDerefParamSet = database.getProperty(target.toXMethod());				if (targetDerefParamSet == null) {					// Hmm...no information for this target.					// Just ignore it.					continue;				}								derefParamSet.intersectWith(targetDerefParamSet);			}						if (derefParamSet.isEmpty()) {				return;			}						IsNullValueFrame invFrame = null;			if (IGNORE_DEREF_OF_NONNULL && invDataflow != null) {				invFrame = invDataflow.getFactAfterLocation(location);				if (!invFrame.isValid()) {					invFrame = null;				}			}			//			int numParams = target.			for (int i = 0; i < numParams; i++) {				if (!derefParamSet.isNonNull(i)) {					continue;				}								int argSlot = invFrame.getArgumentSlot(i, numParams);				if (invFrame != null) {					IsNullValue val = invFrame.getValue(argSlot);					if (val.isDefinitelyNotNull()) {						continue;					}				}								fact.addDeref(vnaFrame.getValue(argSlot), location);			}		} catch (ClassNotFoundException e) {			AnalysisContext.reportMissingClass(e);		}	}