#fixed code
                                public Block getBlock(String blockHash) throws Exception {
        byte[] key = SerializeUtils.serialize(BLOCKS_BUCKET_PREFIX + blockHash);
        return (Block) SerializeUtils.deserialize(rocksDB.get(key));
    }
#vulnerable code 
                                public Block getBlock(String blockHash) throws Exception {
        return (Block) SerializeUtils.deserialize(rocksDB.get((BLOCKS_BUCKET_PREFIX + blockHash).getBytes()));
    } 
                            #location 2 
                            #vulnerability type THREAD_SAFETY_VIOLATION