#fixed code
                                public String getAppiumServerPath(String host) throws Exception {
       return appiumServerProp(host, "appiumServerPath");
    }
#vulnerable code 
                                public String getAppiumServerPath(String host) throws Exception {
        JSONArray hostMachineObject = CapabilityManager.getInstance().getHostMachineObject();
        List<Object> objects = hostMachineObject.toList();
        Object o = objects.stream().filter(object -> ((HashMap) object).get("machineIP")
                .toString().equalsIgnoreCase(host)
                && ((HashMap) object).get("appiumServerPath") != null)
                .findFirst().orElse(null);
        if (o != null) {
            return ((HashMap) o).get("appiumServerPath").toString();
        }
        return null;
    } 
                            #location 9 
                            #vulnerability type NULL_DEREFERENCE