protected byte[] onDataGet(final long logIndex, final byte[] value) throws IOException {
        return value;
    }
Called after getting data from rocksdb.

@param logIndex the log index
@param value    the value in rocksdb
@return the new value
jraft-core/src/main/java/com/alipay/sofa/jraft/storage/impl/RocksDBLogStorage.java