IsNullValueDataflow invDataflow = invDataflowMap.get(method); if (invDataflow == null) { MethodGen methodGen = getMethodGen(method); CFG cfg = getCFG(method); ValueNumberDataflow vnaDataflow = getValueNumberDataflow(method); DepthFirstSearch dfs = getDepthFirstSearch(method); AssertionMethods assertionMethods = getAssertionMethods();  IsNullValueAnalysis invAnalysis = new IsNullValueAnalysis(methodGen, cfg, vnaDataflow, dfs, assertionMethods); invDataflow = new IsNullValueDataflow(cfg, invAnalysis); invDataflow.execute();  invDataflowMap.put(method, invDataflow); } return invDataflow;
return invDataflowFactory.getAnalysis(method);
	public IsNullValueDataflow getIsNullValueDataflow(Method method) throws DataflowAnalysisException, CFGBuilderException {		IsNullValueDataflow invDataflow = invDataflowMap.get(method);		if (invDataflow == null) {			MethodGen methodGen = getMethodGen(method);			CFG cfg = getCFG(method);			ValueNumberDataflow vnaDataflow = getValueNumberDataflow(method);			DepthFirstSearch dfs = getDepthFirstSearch(method);			AssertionMethods assertionMethods = getAssertionMethods();			IsNullValueAnalysis invAnalysis = new IsNullValueAnalysis(methodGen, cfg, vnaDataflow, dfs, assertionMethods);			invDataflow = new IsNullValueDataflow(cfg, invAnalysis);			invDataflow.execute();			invDataflowMap.put(method, invDataflow);		}		return invDataflow;	}