if (handle != basicBlock.getFirstInstruction()) { return; } BasicBlock fallThroughPredecessor = cfg.getPredecessorWithEdgeType(basicBlock, EdgeTypes.FALL_THROUGH_EDGE); if (fallThroughPredecessor == null || !fallThroughPredecessor.isNullCheck()) { return; }   ValueNumberFrame vnaFrame = vnaDataflow.getStartFact(fallThroughPredecessor); if (!vnaFrame.isValid()) {   makeFactTop(fact); return; } ValueNumber vn = vnaFrame.getInstance(handle.getInstruction(), methodGen.getConstantPool());
	public void transferInstruction(InstructionHandle handle,			BasicBlock basicBlock, UnconditionalValueDerefSet fact)			throws DataflowAnalysisException {		// TODO: implement this	}