#vulnerable code 
                                @Override
    public void configure(Map<String, ?> operand) {
        super.configure(operand);
        if (getRowType() == null) {
            throw new IllegalStateException("Custom tables not yet supported for Kafka");
        }
        int epoch = (Integer) operand.get("epoch");
        org.apache.avro.Schema avroSchema = (org.apache.avro.Schema) operand.get("avroSchema");
        Pair<org.apache.avro.Schema, org.apache.avro.Schema> schemas = getKeyValueSchemas(avroSchema);
        String id = getName() + "_" + epoch;
        Map<String, Object> configs = new HashMap<>(operand);
        configs.put(KafkaCacheConfig.KAFKACACHE_TOPIC_CONFIG, id);
        configs.put(KafkaCacheConfig.KAFKACACHE_GROUP_ID_CONFIG, id);
        configs.put(KafkaCacheConfig.KAFKACACHE_CLIENT_ID_CONFIG, id);
        configs.put(KafkaCacheConfig.KAFKACACHE_ENABLE_OFFSET_COMMIT_CONFIG, true);
        String enableRocksDbStr = (String) configs.getOrDefault(KarelDbConfig.ROCKS_DB_ENABLE_CONFIG, "true");
        boolean enableRocksDb = Boolean.parseBoolean(enableRocksDbStr);
        String rootDir = (String) configs.getOrDefault(
            KarelDbConfig.ROCKS_DB_ROOT_DIR_CONFIG, KarelDbConfig.ROCKS_DB_ROOT_DIR_DEFAULT);
        Comparator<byte[]> cmp = new AvroKeyComparator(schemas.left);
        Cache<byte[], byte[]> cache = enableRocksDb
            ? new RocksDBCache<>(id, "rocksdb", rootDir, Serdes.ByteArray(), Serdes.ByteArray(), cmp)
            : new InMemoryCache<>(cmp);
        this.rows = new KafkaCache<>(
            new KafkaCacheConfig(configs), Serdes.ByteArray(), Serdes.ByteArray(), null, cache);
    } 
                            #location 7 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public void configure(Map<String, ?> operand) {
        super.configure(operand);
        if (getRowType() == null) {
            throw new IllegalStateException("Custom tables not yet supported for Kafka");
        }
        Map<String, Object> configs = new HashMap<>(operand);
        String groupId = (String) configs.getOrDefault(KafkaCacheConfig.KAFKACACHE_GROUP_ID_CONFIG, "kareldb-1");
        int epoch = (Integer) configs.get("epoch");
        org.apache.avro.Schema avroSchema = (org.apache.avro.Schema) configs.get("avroSchema");
        Pair<org.apache.avro.Schema, org.apache.avro.Schema> schemas = getKeyValueSchemas(avroSchema);
        String topic = getName() + "_" + epoch;
        configs.put(KafkaCacheConfig.KAFKACACHE_TOPIC_CONFIG, topic);
        configs.put(KafkaCacheConfig.KAFKACACHE_GROUP_ID_CONFIG, groupId);
        configs.put(KafkaCacheConfig.KAFKACACHE_CLIENT_ID_CONFIG, groupId + "-" + topic);
        configs.put(KafkaCacheConfig.KAFKACACHE_ENABLE_OFFSET_COMMIT_CONFIG, true);
        String enableRocksDbStr = (String) configs.getOrDefault(KarelDbConfig.ROCKS_DB_ENABLE_CONFIG, "true");
        boolean enableRocksDb = Boolean.parseBoolean(enableRocksDbStr);
        String rootDir = (String) configs.getOrDefault(
            KarelDbConfig.ROCKS_DB_ROOT_DIR_CONFIG, KarelDbConfig.ROCKS_DB_ROOT_DIR_DEFAULT);
        Comparator<byte[]> cmp = new AvroKeyComparator(schemas.left);
        Cache<byte[], byte[]> cache = enableRocksDb
            ? new RocksDBCache<>(topic, "rocksdb", rootDir, Serdes.ByteArray(), Serdes.ByteArray(), cmp)
            : new InMemoryCache<>(cmp);
        this.rows = new KafkaCache<>(
            new KafkaCacheConfig(configs), Serdes.ByteArray(), Serdes.ByteArray(), null, cache);
    }