#vulnerable code 
                                @Override
    protected void parse(NulsByteBuffer byteBuffer) throws NulsException {
        alias = new String(byteBuffer.readByLengthByte());
        address = new Address(new String(byteBuffer.readByLengthByte()));
        encryptedPriKey = byteBuffer.readByLengthByte();
        pubKey = byteBuffer.readByLengthByte();
        status = (int)(byteBuffer.readVarInt());
        extend = byteBuffer.readByLengthByte();
    } 
                            #location 4 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    protected void parse(NulsByteBuffer byteBuffer) throws NulsException {
        address = Address.fromHashs(byteBuffer.readByLengthByte());
        alias = new String(byteBuffer.readByLengthByte());
        encryptedPriKey = byteBuffer.readByLengthByte();
        pubKey = byteBuffer.readByLengthByte();
        status = (int) (byteBuffer.readByte());
        extend = byteBuffer.readByLengthByte();
    }