#vulnerable code 
                                @Override
    public void init() {
        cacheService = LedgerCacheService.getInstance();
        registerService();
        ledgerService = NulsContext.getServiceBean(LedgerService.class);
        coinManager = UtxoCoinManager.getInstance();
        UtxoOutputDataService outputDataService = NulsContext. getServiceBean(UtxoOutputDataService.class);
        coinManager.setOutputDataService(outputDataService);
        ledgerService.init();
        addNormalTxValidator();
        UtxoCoinDataProvider provider = NulsContext.getServiceBean(UtxoCoinDataProvider.class);
        provider.setInputDataService(NulsContext.getServiceBean(UtxoInputDataService.class));
        provider.setOutputDataService(outputDataService);


        this.registerTransaction(TransactionConstant.TX_TYPE_COIN_BASE, CoinBaseTransaction.class, CoinDataTxService.getInstance());
        this.registerTransaction(TransactionConstant.TX_TYPE_TRANSFER, TransferTransaction.class, CoinDataTxService.getInstance());
        this.registerTransaction(TransactionConstant.TX_TYPE_UNLOCK, UnlockNulsTransaction.class, CoinDataTxService.getInstance());
        this.registerTransaction(TransactionConstant.TX_TYPE_LOCK, LockNulsTransaction.class, CoinDataTxService.getInstance());
    } 
                            #location 9 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public void init() {
        cacheService = LedgerCacheService.getInstance();
        registerService();
        ledgerService = NulsContext.getServiceBean(LedgerService.class);
        coinManager = UtxoCoinManager.getInstance();
        UtxoOutputDataService outputDataService = NulsContext.getServiceBean(UtxoOutputDataService.class);
        coinManager.setOutputDataService(outputDataService);
        addNormalTxValidator();
        this.registerTransaction(TransactionConstant.TX_TYPE_COIN_BASE, CoinBaseTransaction.class, CoinDataTxService.getInstance());
        this.registerTransaction(TransactionConstant.TX_TYPE_TRANSFER, TransferTransaction.class, CoinDataTxService.getInstance());
        this.registerTransaction(TransactionConstant.TX_TYPE_UNLOCK, UnlockNulsTransaction.class, CoinDataTxService.getInstance());
        this.registerTransaction(TransactionConstant.TX_TYPE_LOCK, LockNulsTransaction.class, CoinDataTxService.getInstance());
    }