#vulnerable code 
                                @Override
    public void doRender(RunTemplate runTemplate, NumbericRenderData numbericData, XWPFTemplate template)
            throws Exception {
        NiceXWPFDocument doc = template.getXWPFDocument();
        XWPFRun run = runTemplate.getRun();
        List<TextRenderData> datas = numbericData.getNumbers();
        Style fmtStyle = numbericData.getFmtStyle();

        BigInteger numID = doc.addNewNumbericId(numbericData.getNumFmt());
        
        XWPFParagraph paragraph;
        XWPFRun newRun;
        for (TextRenderData line : datas) {
            paragraph = doc.insertNewParagraph(run);
            paragraph.setNumID(numID);
            CTP ctp = paragraph.getCTP();
            CTPPr pPr = ctp.isSetPPr() ? ctp.getPPr() : ctp.addNewPPr();
            CTParaRPr pr = pPr.isSetRPr() ? pPr.getRPr() : pPr.addNewRPr();
            StyleUtils.styleRpr(pr, fmtStyle);
            newRun = paragraph.createRun();
            StyleUtils.styleRun(newRun, line.getStyle());
            newRun.setText(line.getText());
        }

        // 成功后清除标签
        clearPlaceholder(run);
        IRunBody parent = run.getParent();
        if (parent instanceof XWPFParagraph) {
            ((XWPFParagraph) parent).removeRun(runTemplate.getRunPos());
            // To do: 更好的列表样式
            // ((XWPFParagraph) parent).setSpacingBetween(0,
            // LineSpacingRule.AUTO);
        }
    } 
                            #location 29 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public void doRender(RunTemplate runTemplate, NumbericRenderData numbericData, XWPFTemplate template)
            throws Exception {
        NiceXWPFDocument doc = template.getXWPFDocument();
        XWPFRun run = runTemplate.getRun();
        List<TextRenderData> datas = numbericData.getNumbers();
        Style fmtStyle = numbericData.getFmtStyle();

        BigInteger numID = doc.addNewNumbericId(numbericData.getNumFmt());

        XWPFParagraph paragraph;
        XWPFRun newRun;
        for (TextRenderData line : datas) {
            paragraph = doc.insertNewParagraph(run);
            paragraph.setNumID(numID);
            CTP ctp = paragraph.getCTP();
            CTPPr pPr = ctp.isSetPPr() ? ctp.getPPr() : ctp.addNewPPr();
            CTParaRPr pr = pPr.isSetRPr() ? pPr.getRPr() : pPr.addNewRPr();
            StyleUtils.styleRpr(pr, fmtStyle);
            newRun = paragraph.createRun();
            StyleUtils.styleRun(newRun, line.getStyle());
            newRun.setText(line.getText());
        }

    }