public IsNullValueFrameModelingVisitor(ConstantPoolGen cpg, AssertionMethods assertionMethods) {
public IsNullValueFrameModelingVisitor( ConstantPoolGen cpg, AssertionMethods assertionMethods, ValueNumberDataflow vnaDataflow) {
	public IsNullValueFrameModelingVisitor(/*IsNullValueAnalysis analysis, */ConstantPoolGen cpg, AssertionMethods assertionMethods) {		super(cpg);//		this.analysis = analysis;		this.assertionMethods = assertionMethods;	}