#fixed code
                                @Override
    public List<Device> getDevices(String machineIP, String platform) throws Exception {
        ObjectMapper mapper = new ObjectMapper()
                .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        List<Device> devices = new ArrayList<>();

        if (platform.equalsIgnoreCase(OSType.ANDROID.name()) ||
                platform.equalsIgnoreCase(OSType.BOTH.name())) {
            List<Device> androidDevices = Arrays.asList(mapper.readValue(new URL(
                            "http://" + machineIP + ":4567/devices/android"),
                    Device[].class));
            Optional.ofNullable(androidDevices).ifPresent(devices::addAll);
        }
        if (platform.equalsIgnoreCase(OSType.iOS.name()) ||
                platform.equalsIgnoreCase(OSType.BOTH.name())) {
            if (CapabilityManager.getInstance().isApp()) {
                if (CapabilityManager.getInstance().isSimulatorAppPresentInCapsJson()) {
                    List<Device> bootedSims = Arrays.asList(mapper.readValue(new URL(
                                    "http://" + machineIP + ":4567/devices/ios/bootedSims"),
                            Device[].class));
                    Optional.ofNullable(bootedSims).ifPresent(devices::addAll);
                }
                if (CapabilityManager.getInstance().isRealDeviceAppPresentInCapsJson()) {
                    List<Device> iOSRealDevices = Arrays.asList(mapper.readValue(new URL(
                                    "http://" + machineIP + ":4567/devices/ios/realDevices"),
                            Device[].class));
                    Optional.ofNullable(iOSRealDevices).ifPresent(devices::addAll);
                }
            } else {
                List<Device> iOSDevices = Arrays.asList(mapper.readValue(new URL(
                                "http://" + machineIP + ":4567/devices/ios/realDevices"),
                        Device[].class));
                Optional.ofNullable(iOSDevices).ifPresent(devices::addAll);
            }
        }
        return devices;
    }
#vulnerable code 
                                @Override
    public List<Device> getDevices(String machineIP, String platform) throws Exception {
        ObjectMapper mapper = new ObjectMapper()
                .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        List<Device> devices = null;

        if (platform.equalsIgnoreCase(OSType.ANDROID.name()) ||
                platform.equalsIgnoreCase(OSType.BOTH.name())) {
            devices.addAll(Arrays.asList(mapper.readValue(new URL(
                            "http://" + machineIP + ":4567/devices/android"),
                    Device[].class)));
        }
        if (platform.equalsIgnoreCase(OSType.iOS.name()) ||
                platform.equalsIgnoreCase(OSType.BOTH.name())) {

            if (CapabilityManager.getInstance().isApp()) {

                if (CapabilityManager.getInstance().isSimulatorAppPresentInCapsJson()) {
                    devices.addAll(Arrays.asList(mapper.readValue(new URL(
                                    "http://" + machineIP + ":4567/devices/ios/bootedSims"),
                            Device[].class)));
                }
                if (CapabilityManager.getInstance().isRealDeviceAppPresentInCapsJson()) {
                    devices.addAll(Arrays.asList(mapper.readValue(new URL(
                                    "http://" + machineIP + ":4567/devices/ios/realDevices"),
                            Device[].class)));
                }
            } else {
                devices.addAll(Arrays.asList(mapper.readValue(new URL(
                                "http://" + machineIP + ":4567/devices/ios"),
                        Device[].class)));
            }
        }
        assert devices != null;
        return devices;
    } 
                            #location 9 
                            #vulnerability type NULL_DEREFERENCE