IsNullValueFrameModelingVisitor visitor = new IsNullValueFrameModelingVisitor(fact, methodGen.getConstantPool());
visitor.setFrame(fact);
	public void transferInstruction(InstructionHandle handle, BasicBlock basicBlock, IsNullValueFrame fact)		throws DataflowAnalysisException {		IsNullValueFrameModelingVisitor visitor =			new IsNullValueFrameModelingVisitor(fact, methodGen.getConstantPool());		handle.getInstruction().accept(visitor);	}